"A.t.p." joke

there was a guy who had to use the bathroom really bad and the men's line was too long
so he asks the lady if he can use the womens and she said "
yes just dont touch any buttons"
he said "
ok i wont"
so he goes in and sits down,
he pushes the first button and it blows up warm water
he says "
that feel good"
so he pushes the second button and it blew up warm air and he said "
ooo that feels good"
he pushed the third button that said A.T.P. under it and the guy said "
i wonder what this does"
so he pushes it and he screams.
what do u think A.T.P. means...
A-automatic
T-tampon
P-puller