you might want to take into consideration what it will look like when you're in your 70s. For a minimum of exhilaration among your future nurses I recommend some section that doesn't massively shrink or wrinkle. Back or calf, perhaps buttock.
Personally, I consider the best place for a man to be tattoed to be nowhere (though admittedly tattoos have the advantage that if the guy is a bore in bed, you can always look at the pics)
See, I never understood this argument. People always ask when I show a tattoo or express interest in getting another, "Well, have you thought about what it will look like when you're 70?" and I'm like, "Yeah, old and wrinkly -- like the rest of me." I really don't get how this is an argument against getting tattoos!