Use a freaking condom and there is no problem.
Hahahaha i actuly laughed out loud when i read the answers
LOL
but ye thnx for the advise so like condom and loads of LUBE (not spit) :D
thnx
Use condoms. Anal sex will invariably involve some feces (hence, what turns most people off). You don't want that getting in your urethra, under your foreskin, or in your girlfriend's vagina (try dealing with *that* kind of bacterial infection and see if she wants to go again... *bleh*). If you're going to do it, use a condom, a LOT of lube (spitting at the beginning won't be enough, unless she doesn't mind bleeding), and don't switch lanes without signalling first. Good luck.