You can't tease me by making that the example and not actually requesting it! The more I think about it the more I want it. Krillin probably saw it in one of Roshi's magazine and has been dying to try it. He finally gets the courage to ask 18 and she thinks it's the best idea ever.

BONUS: They go strap-on shopping together. Krillin tries not to die of shame while for 18 acts like it isn't any different than regular shopping.