My girlfriend says she don't feel anything during sex cause my penis to small? True?

Female Anatomy. Nope. But, many guys are not taught that penetration alone will, in most cases, not cause the clitoris to be manipulated. Men and women have to work on that with intercourse. Using your fingers or your lips and tongue may help her get to orgasm with you. Learn what turns her on. Learn where she likes to be touched. Learn the pressure she needs to feel you deep inside her.