Your mission, if you choose to accept it, is to fill in the blanks.
Sex is only ______ when you ______.
good, snorkel
disturbing, yodel
fun, laugh
multidimensional, use the rubber hose
upside down, are a bat
Sex is only 
when you :eek:
permitted, use it for procreation 
Sex is only painful when you miss
Sex is only dirty when you do it right
$35 bucks, find the right hooker.
Sex is only precocious when you destroy.
(Asked a friend for an adjective & a verb - that’s what he gave me.)
Sex is only ** like spaghetti - chunky, slippery, and red ** when you ** use spaghetti sauce. **
Sex is only beautiful when you run.
Another “Mad Lib” courtesy of Mrs. Smith!
dangerous, try it in a hot tub.
Sex is only gigantic when you are angling.
(Mad Lib courtesy of Max Torque. Unsuspecting mad libs are fun!)
Courtesy of the vaguely confussled people I accosted online:
Sex is only fast when you beckon.
Sex is only hungry when you coagulate.
I agree totally withMnementh. They’re very fun. (now, where’s that evil smiley when you need it?)
Sex is only crazy when you jump.
(that one courtesy of my sister)
F_X
ducky, a duck.
natural, horny.
a day away, wish upon a star