Dude let her go. There are men that woild give their right arm to be with a wonan that has that desire. If you two are not a sexual match you can try to force it, but eventually it will fail. If this is that big of a deal to her then perhaps she is not as sexually satisfied in the relationship as you think. Why should she not have what she wants, Why should you have to be preasured into things you dont want. If this is that important to her, she will eventually find a guy who is into it. and either leave ir cheat. The number of men with the desire to get pegged is way too high for you two to suffer.

I think it's time to see other people

Time for a new girlfriend!

do it its not so bad

Is your girlfriend by chance the one going to a kid's toy store asking if they sell ******? (Note FML previous to this)

not cool

There is no indication that she is "trying to get him back" for something. If he said no, it means NO. FMLs have had similar topics before without them being from the same person/people. His gf is so wrong if she is actually wanting to do this when he already said no.

the one eye u sleep with open shouldnt be your brown eye...

Say good bye to your black cherry

Buy some lube. Prepare yourself. Literally.