Is this racist?

Particualrly a Pakistani that isn't one of your mates. A random member of the public?

c.f. A joke about gay sex to a gay person; a gender oriented joke to a woman; a paddy joke to an irishman; a 'spastic' joke to a person in a wheelchair, etc.

A very good litmus test, i think.

of course, such philosophising over what is acceptable or not; what is over the line etc has very little effect on our actual behaviour (I include myself in this).

Personally I love them and tell them pretty often, I don't have a problem with them. So I think it's a load of PC shit to be honest.