I know quite a few girls who think it's gross
to have a guy cum in your mout, or on your
face, or body or otherwise anywhere...

...I SO do not identify! I love cum.
LOVE it. I love the taste, the texture, the slick
heat.  I love what it represents... the inequovical
physical reality of a man's pleasure,which I coaxed
from him. It is a bitter sweet reward for what I did.

I wouldn't say that I'm a slut or anything, but one
really cannot underestimate the slippery seductive
powers of a nice pretty blowjob. Or half a dozen.
Basically, blowjobs can be used for reward-punishment
scenareos... especially if I tenderly provide them so
often that he is conditioned to be cumming in my mouth
on a near daily basis... just *happening* to not do it
on a particular day reminds him he'd better behave! 

And if you're good?  

blowjob.