3 or More
Each player has a shot glass filled in front of them. The first player starts by singing a Christmas jingle and stops after the first line of the song. The next person must sing the next line of the song, and so on.
If the player sings the song incorrectly or doesn’t know the lyrics they must take a shot. If you manage to finish the jingle, the player that sings the last line of the song is immune from taking a shot next round.