First of all, sorry for the double post.
I had a second look on the Offbeatr-Demo-Video and the really good looking blow job, and suddenly an idea crossed my mind: What about reciprocity? What if the player could turn the sporty girl around and bend her over the couch, bite her juicy ass and make her giggle by plunging his tongue into her delicate pussy lips or her lovely butt cheeks?
I mean, it would greatly enhance the immersion if the player has a mouth, too.
I would suggest that it was transparent and placed in the middle of the lower half of the display. There are three modes for it that I currently think of: Suck, tongue/lick, (softly) bite/nibble. I don't know if the mouse wheel is currently used for anything, but if not, then I would say that it could be used to adjust the intensity of the "mouth action".

(Of course, corresponding reactions from her would be very welcome, e.g. soft licking lead to quiet sighs and closed eyes, hard sucking results in loud moans and eyes rolling to the back of her head.)
EDIT: (This would make the "69"-position possible.

Oops. I forgot kissing.

)
2nd EDIT: Although I am not a fan of it, spitting could be the fourth mode or an additional function for the other three modes, especially for anal foreplay.