3 nurses go into the morgue, and there's a dead man's body lying there, with an erection.
The first nurse sees it, and says "I'm gagging for it", gets atop the man and has her way with it.
The second nurse says "Aye, so am I, shame to let it go to waste", and she does the same.
They turn to the 3rd nurse and ask her if she is having a go. She replies she is having her period, and declines. One of the nurses reply "He's dead anyway, he'll no bother". The last nurse agrees with this, gets on and does her thing too.
Just after she finishes, the dead man sits up. The nurses ask him "We thought you were dead!", and the man replies,
"After two jump starts and a blood transfusion, you wouldn't be dead either!".