Hailey Bieber caused a stir at the Met Gala ... and Justin Bieber watched his hockey team play a stirring playoff game.
Hailey was spotted walking around Monday's big fashion event with a martini glass in hand ... with Justin nowhere to be found.
The Biebs posted on his social media, though ... and he was busy watching his Toronto Maple Leafs win the first game of their NHL postseason series with the Florida Panthers.