A student in 30 vies called Kevin dislikes the way that Louis-Vincent acts in class. (Louis-Vincent is obnoxious.)
Kevin tells him straight out what he thinks about his behaviour. Louis-Vincent feels attacked, so he bites back by poking fun at Kevin’s physical disability.
A third student overhears Louis-Vincent’s comment to Kevin. He disapproves of his comment by telling him:
C’est un peu cheap.
That’s a bit low.
Sometimes you’ll hear cheap used informally to refer to the poor quality of something, or to someone’s stinginess. But here it’s used to refer to Louis-Vincent’s lack of decency, the cheap shot that he took.
[Quote from 30 vies, season 2, episode 91, Radio-Canada, Montreal, 29 February 2012.]