We already knew that "Bieber fever" can strike people of all ages, but it's never been exemplified better than in the video below.
Two girls the age of typical Bieber fans attempt to record themselves singing and dancing to Bieber's "Baby" in their living room, but dad ends up stealing the show with his far more dedicated dance routine.
Whether they enlisted him to help spice up their tribute, or he did the dance-video equivalent of a photobomb, we don't know. However, It's pretty obvious who the biggest Bieber fan is in this video, and he is far from "baby" age. (Via Buzzfeed)