Is swinging a good idea in this situation?

[Mike]

My girlfriend and I have been together almost three years. We have a great relationship, can talk about almost anything and are very open and honest with each other. She has had plenty of 'fun' over the years before our relationship, and while I was no saint, I only lost my virginity to her at age 26. My lack of wild oats being sown has therefore been an unspoken elephant in the room. The other day it finally came up for conversation and she was very understanding, saying she could see I'd want to try sex with other people, and that she'd always though I'd want to try it with others. We talked about sex with others generally, and she said while she'd do soft swinging - that is having sex while being watched and watching others - she doesn't think she could handle seeing me with someone else. There is no getting away from it though; I think about sex with other women a LOT! I know all guys do but I think I do it more, due to my late loss of virginity. She said she'd expect so too. The only thing I can think of - apart from either breaking up, or accepting I can never have sex with another - is swinging. Views? Part of me can understand the appeal. If we're in it together and know it's only sex and nothing more, I think I'd be less upset. But not sure, Very confused.