Zuko walks in on Sokka in a compromising position.
Sokka: What are you doing here?
Zuko: Hey, sorry. I need your help. Is this a bad time?
Sokka: Suki’s outside, I’m in my sexy pajamas, I just took four Benadryls to dull my sensitivity… Yes, it is a bad time.
Zuko: You’re about to have sex.
Sokka: Why else would Boyz II Men’s “On Bended Knee” be playing right now?