Paddy the Irishman is on holiday with his girlfriend in Las Vegas.

Paddy the Irishman is on holiday with his girlfriend in Las Vegas.
One night they, after paying a fortune for tickets, they go out to
a club where, as paddy assures his friend, they will mingle with
the stars. Sure enough the place is full of stars, and everyone
seems to know everyone else with "Hiya Madonna" and "how do Clint"
all over the place.

Paddy's girlfriend is decidedly unimpressed that Paddy knows none of
these stars, and nobody is interested in talking to them. On a visit
to the toilet Paddy finds himself standing beside Frank Sinatra.
Paddy explains the problem to him, tells him that he has been a
fan for years and has all the records and asks him to help him out.

All he has to do is walk past Paddy's table and shout "Howya Paddy".
Frank is in a good mood so agrees to do this.

Twenty minutes later sure enough Frank walks up to the table where
Paddy and his girlfriend are sitting alone talking. "Howya Paddy"
shouts Frank. Paddy turns round and says "Will you ever f**k off Frank,
can't you see that I'm talking to my girlfriend?"