I'm sure the outcome isn't for invitro.
"Well, let's see. What happens when you milk a male horse?
I'm sure the outcome isn't for invitro."
Psst. The horse would have been a gelding, 90%+ odds of that.
Besides, I guess my mind isn't dirty enough. When I read this joke, I imagined W. taking the gelding to a barn, tying the reins, squatting down on a milking stool, reaching up, and saying, "Whoops! Sorry, there bud!"