Its on the tip of my tongue...
When you go to kiss your grandma goodbye and she slips you the tongue.
They have the gift of tongues...
Ebola cereal!
Red paint! Whats green, and smells like red paint Green paint :) Can't believe how many time I switch to the second, and they don't get it!
When you get there, you turn into the driveway. Ba-dum-bum! Don't forget to tip your waitress!
When the terrorists asked for anything cheaper than one-way.
Chemistry, because there is lots of acid involved.
A Klingon! since obstetrician gynaecologist is too long, and OB GYN doesn't make sense,lets call them Klingons