While it's sexy for a gal to bite her lips during sex
it also means you cannot french her if she does that
instead it's a great turn on if she heaves her bottom
to meet your thrusts, as your dick gets swallowed by her pussy head-on
with her legs wrapped around you and her toes all curled up

while her fists rained repeatedly but lightly on your back non-stop
then she shakes her head left to right as if she's protesting
as you watch her beautiful face, contorted in ecstatic grimacing
a scene like this is the climax I enjoy most in my love-making