Bieber
To faux stab, faux shank, or injury someone only for their discomfort but your and everyone else's amusement whilst singing a Justin Bieber lyric.
*Sneak up on someone with a pen in your hand, as you jab their side you say* "BIEBER!"

or

Singing a Justin Bieber song, you faux-stab on "oooh!" as such..."It's like baby baby baby OOOH!"