Alice and Bob are two students who are habitual cheaters.
Alice to Bob: You really should stop cheating on your exams.
Bob to Alice: I'll stop cheating if you stop cheating too.
Does the hypothetical argument above fall under whataboutism? It seems borderline to me. In this argument, Bob doesn't deny that Alice is right, but they refuse to stop cheating with a rationale that indirectly criticizes Alice for hypocrisy. The latter seems like a hallmark of whataboutism.
Related: Why is "Whataboutism" often criticized? and How can I respond to Whataboutism?