I can't believe I missed a post! I must be slipping...
Well, first and foremost I'd like to address your sexual orientation. You list yourself as 90% gay, do you really WANT to sleep with this woman? You should only do it if YOU are into it, not just to please her. You say you're intrigued by her, so I'll just go with that for now.
I assume she already knows about your size, I've seen your pics, and while quite thick, it doesn't look unmanagable to me. Your shape is tapered which helps with entry, and girth is easier than length for most women to accomodate because of the way the vagina stretches. Just make sure she is very wet before you attempt entry, or use lube, and be prepared with condoms that fit! There's nothing more annoying than having to listen to a guy complain about how restrictive they are when they know they have a big dick to start with. Remember to take your time, most women need some foreplay to get in the mood, so let her set the pace and you'll both probably have the time of your lives. If she's a woman who appreciates size, it will probably be a real treat for her, just don't forget about yourself. As always, love yourself, respect each other, practise safe sex, and have some fun!