I'm posting this here because I want SERIOUS replies and/or SERIOUS suggestions/advice only Even when I use lubrication and when we foreplay and oral sex, penetration is still difficult and after a couple of tries I get frustrated and lose my erection. We have also tried different positions such as her on top, me on top and also me from behind. At first, I thought it was me but I think its the design of her vagina..This may sound silly but I think my girlfriends vagina is too "tight"...its like the muscles inside her vagina are very strong and won't let my penis enter...She tells me she is relaxed and ready. Once during Oral Sex, she pleaded with me too stop because she was so ready to have sex and so we tried but again we could not. In retrospect, I've never had this problem with other female partners. If anyone has any suggestions on this please let me know. We have decided to try again tonite and If it doesn't work tonite then I don't know what we will do. We've already tried everything else and we are both ready to have vaginal intercourse. Thank You. Additional Details - Also I have to add that she said its never really been a problem for her either but with one other partner. she and an ex boyfriend tried three times until they were finally able to have vaginal intercourse. She also takes a long time to achieve orgasm. Once I spent an hour (i think) fingering her until she finally had an orgasm.