Just read a thread about some guy with a large penis and how he hurt his GF internally, from fucking to hard. A poster responded that he probably bruised her posterior fornix or something like that. Others responded with bladder bruising etc. So my question is what is a "safe" size knowing the biology of a woman. Average length(depth?) of a vagina etc. Since there are average length of a penis is there an average depth of a vagina? Of course anything small would be "safe" but given many of you are large-above average, what has been your experience with women who took you comfortably without any bruising or pain?