Really? My favorite sex act only requires what people here shoot off, their mouths, which would now be doing something useful for once.
Biologically no human sex act would include the mouth but thanks for playing.
If you're not using your mouth during sex, you're not playing, you're boring.
Been around all these years and still don't know the difference between sex and foreplay. No wonder you can't recognize the difference between a marriage and what ever it is gays have.