Anal fisting, the next logical step after having sex.
"Dude i got to second base with Jen last night"
"Well you're well on your way to getting to the pitchers mound"
When having sex from behind. Pull out and nut in your hand then wined up like a pitcher and throw it in her face. Immediately following yell "Strike!!! Your Out!"
I was with your mom last night and I finished with a pitchers mound.