My girlfriend and I lost our virginity to each other the week before our 25th birthdays (we're 3 days apart.) I figured, "Hey, I've been masturbating for 15 years - I know when I'm going to cum" and I dove in unprotected. Four pumps later, I pulled out in a big hurry just as I began to spurt.
I got the Plan B pills the next morning and we gave it another try that night - with a condom, that time. Muuuuch more satisfying the second time around, and the sex only continued to get better as time went on.
It wasn't for another few months that we really got into a groove and "clicked" sexually and she was able to achieve orgasm with some regularity from penetration alone. To this day, I don't think she's ever once brought herself to climax without my assistance (she claims to have never masturbated before we met) - and that's kind of a neat feeling, I guess.