It is important to stress that unlike ass-bandits, marmite-miners, fudge-packers, butt-pirates and the like, generally speaking a backdoor burglar will plunder your ass without your consent/and or knowledge.
However, particularly fiesty homosexuals will mutually burgle each others arses, due to the fear/excitement of being caught - like the old fashioned game in which you must steal the keys without the other noticing. In this case, replace keys with butt-fudge.
Guy 1: "Dude my ass is sore today, what the hell happened at Mike's party last night."
Guy 2: "Dunno man but you were pretty drunk and I noticed some dodgy pervert hanging around, perhaps you got your backdoor burgled?"
Guy 1: Hey man, shall we go into Club X tonight? My uncle says its good fun.
Guy 2: Maaaaate. Are you a fucking ass bandit? That place is for backdoor burglars ONLY.