A slobbery willy
A slobbery willy is when you take your dog's slobber-covered finger and jam it in your friend's ear because you're too much of a mess to bother cleaning up.
I just let my dog lick my finger and stuck it in my friend's ear. He’s got slobber all over his face now. I win.
My dog's finger is all slimy and I used it to poke my mate's ear. He looked like he was about to cry.
You used your dog's finger to poke my ear. I'm gonna get you back for that.