Three guys were in a bar.... just having a quiet drink, not disturbing anyone and there was this drunken lairy guy in the corner who kept staring menacingly at one of the three guys.

After about ten minutes the drunk walked over and said: "I've shagged your mum." to the bloke he'd been staring at.

The young man's friends thought this odd, but didn't say anything because their friend seemed fine about it. Anyway, after about ten minutes more, the pisshead came back and said "Your mum's sucked my cock dry and loved it!" And again, the guy just ignored it.

A third time the drunk bloke walked over and said "Your mum howls like a dog when I stick it in her."

And finally the guy breaks. In a fit of anger he shouts back "Dad....just go home, you're drunk and embarassing!"