I will teabag if someone really should've killed me but failed hilariously. I'll also teabag someone back if they teabag me, unless I violated the reason for me teabagging to begin with. If that happens, I'll wave when I respawn. A sort of 'yep, I deserved that...' acknowledgment. Occasionally, I'll teabag in Trials of Osiris because it causes the enemy team to rage a little. Psychological warfare. But I only do that if they're using scrub-friendly weapons (Thorn, TLW, The Messenger, Shadow of Veils, any Sniper with Final Round etc.).