There's just one problem: You'll never be able to type anything on this board that would convince me that this is true.
A picture is worth a thousand words, and your picture (IMHO, and in repeated personal experience) reveals a man who couldn't turn her woman on with a diamond dildo. You look like a "once was", literally. Like a former colege athlete or hungry executive, a man with a goal and a mission who's gone as soft as a marshmallow (physically and mentally). In fact, you look like the majority of the men who I've known during my involvement in the lifestyle, but without the spark, the glint, the intent in your eyes. If I had the money to spare, I'd bet a million dollars that you've never given your wife an entire day of orgasms. And I'm sure that your days of casual married sex are long gone as well, if they'd ever even existed (Don't use the children as an excuse, let her take that one).
You look like the proverbial "two-pump chump", the type of man whose lovemaking skills are the five moves of doom: kiss her until she responds/turns around, finger her until she gets wet, force yourself in as soon as she parts her legs, pump her until you reach orgasm, turn around and go to sleep/work/anything besides staying beside her. You look like your idea of romance is getting home from work before the kids get home from soccer practice. You look like the type of guy who women complain/comment about on Internet boards, as in "I never liked sucking my ex-husband's cock, but all Johnnie has to do is whip it out and I'm going for the gold.", "Eat me!!? Terry? You must be joking!!?", "I asked him to make dinner, because I had another migraine. He gave the kids cold cereal and baloney sandwiches.". Bottom line, you look like a stereotypical middle class Caucasian-American male with what a less-caring person would say possesses a "narcissistic self-complex". And you talk like the kind of guy who visits Internet sex forums and complains about how your wife won't "give up the goods", but balks at the idea of doing anything besides the "lights out, missionary position until he cums, then straight to bed" routine.
Now, despite the tone of the last few paragraphs, I'm going to pretend that I'm a licensed counselor and give some advice. First things first: no swinging, no open relationships, no quickie/drawn-out divorces! The last part is obvious, as there are children who'll be affected. The first two, however, need some detail. Swinging is the icing on the cake of a perfect relationship. An "Open Door" stance is like the cookie at the end of a Subway combo, as far as marriages are concerned. Simply put, they're enhancers, not solutions. If your wife isn't willing to open her legs to you (whether for your cock, fingers or tongue), you don't want to allow her to give into temptation. And with the first two solutions, you'd be giving her a key to a candy store.
(my personal opinion: Your wife looks hotter than a furnace. And she's assumeably reaching her sexual peak, which means that you could "convince" her to do so many things. So many indecent, taboo, naughty things...)
She has a pretty face, a decently formed body (as far as I can tell from the picture) and is still willing to sleep in the same bed with you. Why risk allowing her to meet someone who's probably more experienced than you in bedroom talent or mind games? Swinging? She's a probable lock for any couple who sets eyes on her. And the lifestyle is always looking for "new bisexual" women (if they're single or newly divorced, it's all the better), if you know what I mean. Open relationship? Assuming that she isn't cheating on you at this time, she'd quickly find a local neighbor or migrant worker/handyman or business associate to fulfill her needs. Hell, if she hit on me in a bar I'd come running and leave cum running. And if/when that happens, you're dust in the wind, because (if my experiences are anything resembling normal) a mature woman loves sex like a fat kid loves cake. Then the inevitable divorce talks will begin, and you'll be on this board or another Internet forum blathering about how open marriages can never work, or about how swinging is the death knell of any relationship. And I have plenty of information of the opposite effect, plus quite a bit of information regarding the usual factors that lead to a negative outcome (less-attractive body shape, minor skill set and level of innovation/ingenuity combined with selfish bedroom behaviour, lack of shown desire or inverted/perverted desire {compared to the new male partners}. All in all, an almost textbook case of comparing a gold ring to a tarnished brass ring).
But, you can change all of that with a few steps that don't involve your visiting a bookstore and trying to furtively buy a copy of "The Ethical Slut". And, best of all, they aren't even that difficult to do.
1. The gym. 2 miles running, 2 knots swimming or 5 miles on a stationary bike 2 days a week. Calisthenics/weightlifting/yoga 2 days a week. 6 months from now, if you dedicate yourself, you should be a lot closer to what modern day health professionals would consider to be an optimal weight. And, regardless of your current physical condition, you can fit these workouts in an hour. Less weight on your part=a body that your wife would consider more comfortable to allow on top of her. That's one goal achieved.
2. The library. Libraries are covered in self-help books, relationship books and romance/seduction/sex manuals. Open a book and fucking read it! Learn about things:massage, G-spots, bondage, anything that will remove your current bedroom repertoire from it's current doldrums. If your wife is anything like the majority of American woman on the other side of 30, her body is begging for more orgasms. This is your chance to become a part of her climactic regimen, instead of being/becoming a hindrance.
3. The "talks". Tell her that you're trying to change. She's your wife, not just your resident food cooker/child raiser/house cleaner/orgasm absorber (hopefully). Tell her as much as she needs to know. Tell her that you're going to the gym, and call her when you're getting ready to come home. Tell her about an interesting book that you're reading, then ask her if anything inside sounds interesting. Or try some of the stuff out. Believe me, a 10-15 minute foot rub and a "How was your day?" can go a lot farther than a blunt, "I think that we should go to 'Sensual Shenannigans' this weekend."
4. The kids. Romance killers, the lot of them. There's a reason why active swingers tend to be in the late 30's-mid 50's range. They got married at 18-25, had children, and the last kids are finally out of their hair after 18-25 years of nurturing. If your children are too small, or you live in an unsafe area, suck it up and invest in sound barriers for your bedroom. If they're old enough to be trusted with sleepovers, start finding friends for them. If everything else that I've suggested is working, you'll need the "alone time". After all, they shouldn't be privy to Mommy's cries of "Right there, Notaguru2! OhmiGODDDDD!!"
Bottom line: I'm not a professional. I'm just a guy who entered this thread and saw so many warning signs that I couldn't help but put in my (admittedly) 15 cents. And you should re-read the disclaimer at the top of this post if you honestly believe that I'm out of line with my comments, because (as it says) I know nearly nothing about you. All I know is that you're a married man who either has a large cock or likes looking at large cocks. But, I've been on more than a few sex-based Internet forums. And I've read so many threads in this exact vein that I can see the train coming down the track before I see the searchlights or hear the horns. And, judging from the various swingers who I've known over my ten years in the lifestyle, I can say that my tips work. All of the successful swingers (or, at least happy swingers) that I've known have taken at least two of these tips to heart. Whether it's just a matter of looking more like the man that she married, or fucking her like the men in the romance novels, or treating her like the only women on the planet, or some combination of the three, women tend to respond favorably to these actions. And on those occasions in which the tips didn't work out as expected, the talks will usualy reveal some outlying causes (childhood abuse, suppressed lesbian desires, health/body issues {yes, her health affects her libido}) which can be supplemented by professional, physical or pharmaceutical therapy. Worst case scenario: She doesn't respond in the least, or she reveals herself to be unwilling to change, and you can divorce with a clear conscience. The kids will pout, but they'll understand as they get older.
Best case scenario: You'll have a wife who's as passionate aboout you as you are of her. And, at heart, you sound like a guy who hasn't been able to figure out where things started to go wrong. Make the right decisions, reignite her fire, and she may drag you to the local swingers club.(I'll see you there.) She may not even play, just sit back and watch as her "loving husband" enjoys the attentions of a different woman. (Not likely, but it takes all kinds)
Most likely scenario: You have a decent woman who loves you, but is unable to significantly change her ways. And as long as she knows that you'll come back to her, and that you won't reject her if she makes a diversion or two, she's ready to work things out. She might be of the type who says nothing if you come home late from work, or feels noticeably looser when you return from a business trip. And, as above, she may be willing to accept some less socially acceptable behaviour (clubs, the hotel bar, a pair of handcuffs, etc.)
But, it's your life. Do as you will, I have nothing to do with it.
(Yes, I did see your first posts. Good on you for measuring above average.)