Sit on my face and let me eat lick your hole! 

When I eat ass, I usually prefer either to go at him from behind, a.k.a., doggy-style, or have him lay down with his legs back.  Face-sitting works quite well, too, and sometimes I am in the mood to do it this way.  Whatever you and your partner feel like, just as long as you eat his ass with gusto!  He deserves nothing less, and neither do you.