Selective Bad Boy
Someone who acts like he's tough around people he knows won't be a threat, but as soon as the real threats/badboys appear - they act scared, timid and don't speak with the same aggressive energy at all.
Abdul: I thought Joey from Homerton was really about this road life, but then some yutes from Stratford turned up and stepped to him, and he went bare silent and just let them jack his chain.
Mustafa: That's cause Joey's just a selective bad boy!
Mustafa: That's cause Joey's just a selective bad boy!