WHO COULD THIS BE?

Who would weat a crazy outfit like this?

This weekend, a singer from a group put on this ......stylish (?) look.
But who is it? Who would wear such a, um, 'warm' style outfit? In fact, it's a one-piece pajama suit.
We can tell you that he is a total joker! And tomorrow we'll tell you who he is, if you don't already know.