The act can be malicious eg; sleeping with a friend's parner, or non-malicious such as leaving a friend to face a beating in order to save one's own skin.
Friend two: Yep... Fucking dogcunt.
Friend one: So paul just left you to cop a beating from 3 guys?
Friend two: Yep. If he had've stayed we could have taken them, but I couldn't take three by myself.
Friend one: What a fucking dogcunt.