Apparently Jimmy Kimmel Live has been doing something called Mashup Mondays where they get bands who have names that can pseudo-cleverly mash into one to perform a song together. They seem to mainly be bands/artists from very different genres and/or times, as showcased by this week's combining Panic! at the Disco and Sisqo (Panic! at the Sisqo) to sing the latter's 1999 hit, "Thong Song."
In theory this is a fun idea, though this particular choice in no way plays to Panic singer Brendon Urie's considerable strengths, and it's pretty apparent the live audience doesn't exactly know who Sisqo is. Regardless, if you were around in the late '90s and/or saw Pitch Perfect 2 and are a Panic fan, this makes a relatively fun mash up to watch.