Verb. The act of performing gay anal sex whilst highly intoxicated. The act of becoming 'drunkybummed' can also be associated with any homosexual act performed whilst intoxicated.
drunkybummed - 'Awww man, me and my boyfriend got so drunkybummed on the weekend, it was crazy!'
drunkybumming - 'We were probably drunkybumming for about two hours, he's a fucking champ!'