When it's "that time of the month" and the flow is heavy, so you reach behind yourself and down between your legs to plug it with your thumb, and proceed with anal.
Scott was bleeding so bad from his .50 SLAP round failing, and I didn't have a first aid kit ...so I decided to just give him the Kentucky Plug. I probably should've stopped with just the thumb, but the look on his face when I started unbuttoning my pants was priceless.
When you use one hand to choke a girl out who's in downward dog position, and the other hand to put your thumb in the stink and two (or more) in the pink
"Scottys date said she was too dry so he gave her the ole' Kentucky Plug