There was a time in college when I had to use a diaphragm - didn't want to, but had to for a few months. I didn't like it - it took away all the spontaneity I loved about college sex. Anyway, one guy I really liked had a great cock and I had loved fucking him for about two years, off and on. All of a sudden, after a few weekends together, he just didn't seem interested in getting into my vagina, but never turned down a handjob or blowjob. I asked - he said "It hurt". So, after convincing him to get inside me, I could tell he was less than enthusiastic in his normal wonderful pounding. Afterwards I checked, and he was bruised! The tip of his cock was actually bruised! Damn diaphragm!. His cock was (still is) about 7 inches, but we managed to keep his thrusts to about 5, at least until I could dump the diaphragm. Normally, 8 inches is comfortable, I start to feel too much pounding at around 9. Had one bf with a 9 - he had to hold back.