InstagramJustin Bieber is finally 21 ... making him the most deserving of your #ManCrushMonday love.
Check out the 21 hottest reasons to celebrate the Biebs today -- one for every candle on his cake!
21.
20.
19.
18.
17.
16.
15.
14.
13.
12.
11.
10.
9.
8.
7.
6.
5.
4.
3.
2.
1.
ncG1vNJzZmivp6x7tbnZZ5qopV9nfXKBjmlqaGhiZLe2v9OipWaamZqvpr6MrayrpqNif3J5waKpraCUlsZutM6tZKmgn6m8tHnMnKRo