When a man has sex with another mans through his penis. Usually one member has a smaller penis and is the giver, where as the reciever has a larger penis to accomadate for the otherwise uncomfortable insertion.
"so dave, our relationship is very strong now and i wanna try something new..."
"No we are not having dick sex Tom"
"I fancy dick sex...get the tape measure John, lets see who's taking one for the team"