As mike said, being fairly girthy, too tight can be a lot of work and painful for the woman on the receiving end. Used to have a fuck buddy who had only been with a couple guys prior to me, i was her first casual relationship and she was a tiny thing, first time we tried she couldn't take me, next time we got it with a lot of lube but it was a slow go, we fucked for many years and although she got used to it i could never really fuck her hard because she couldn't take it