Try this one. When it was told to me, I suspected it was going to be dodgy but I think its ok:-
There are three expectant fathers waiting in the waiting room. An Englishman, A Welshman and an Indian. The doctor comes out to them and tells them he has good news and bad news. The good news is that all births went fine and all babies are healthy. The bad news is that they have mixed the babies up.
He suggests that they all go in and pick the baby they think is most likely theirs. The English man goes first and comes out with a brown baby. The Indian, clearly upset, asks what he is playing at as that baby was obviously his. The Englishman replies:-
"Look, there's a two to one chance I might pick a Welsh baby. I'm not taking that risk."
Aplogies to any Welsh visitors.