Why should you change? All my mates are lads, there are 7 close ones and around 15 other ones who I hang out with fairly regularly, as well as all the lads I went to school with, and I'm undoubtedly one of the lads. My mate Hoggy calls me a 'bloke with boobs' and my boyfriend doesn't mind for one second because although I like doing blokey things, and I've always been a tomboy, he can see who I am and appreciate the fact that I can hang out with his mates without being shy or weird about it. It seems like that's what you've been doing anyway, because you've got mutual male friends. I'd say go for it, however I'll warn you now, if you separate, and especially if the other lads have been friends with him for longer than you have, then they'll most likely not hang out with you much anymore. Whatever happens though, don't change yourself.