Most girls get shocked or surprised by shaved men. They claim they don't like it but I don't know if that's sincere.
In any case you can always trim with a short beard trimmer or scissors, or taper from the scrotum toward a shaved crack. If your whole ass is hairy don't shave outside of the crack interior.
Basically pay attention to when you poop and when you feel the need to poop and don't get a rimjob then. If you've pooped recently, just try to poop again in a few minutes, then stand at the sink or shower and stick your finger in your ass while pushing. Shit on your finger? Wash it off and repeat. If it won't stop being poopy, then shit again or wait until later.
I know it sounds gross but really that's what soap and water is fucking for. Wash your fingers thoroughly and it's no big deal.