An ofasm is much like a female orgasm except it is entirely in the head of the male "performer". Typically the male imagines her having a real orgasm because he is inept yet clueless to this reality. It is unlike a faked orgasm in that the female does not have to actually do anything, the male is just retarded. and inept. and retarded.
Last night Vern gave 3 ofasms to his girlfriend, much to her chagrin.