1. When you cockblock but unknowlingly do it
2. To interrupt a private moment or conversation with two people by accident or unintentionally
3.To make up for your accidental cockblocking afterwards you say U.A.C.
Friend:Man you totally ruined me and Jesse's convo,i was about to get her number.Cockblocker!
Friend:My fault U.A.C.(Unintentional Accidental Cockblocking)
Friend: Alright man its cool then