I had a friend who was fooling around with his girlfriend while I was in the car with them. She started touching him through his clothes, and he said, "Aaaaand Houston, we have liftoff!"
Other ideas include "Fire in the hole!" and, of course, "...Aaaand boom goes the dynamite!"
Other ideas include "Fire in the hole!" and, of course, "...Aaaand boom goes the dynamite!"