When a male with a smaller penis inserts his genitals into the
urethra of another man's much larger penis and proceeds to
thrust in and out, thus resulting in penis fucking.
Big Dick:
unnh my dick wont fit into your ass, wanna just do some penis fucking tonight?
Small Dick: sure (inserts penis into other mans penis)
unh yeah feels like a pussy
Big Dick:
mmmm fuck yeah, hard and deep
Small Dick: I'm cumming! (shoots a huge load into the larger penis)