Growing up, Mason was a jock with jock things.
Henry was not a jock, but he liked jock things (and Mason).
Mason knows Henry likes jock things like he would like some girl things (like a pair of panties from the head cheerleader he had). It would never really occur to high school meathead Mason that it wasn't just that Henry liked HIS jock things in particular, he just figured they were the easiest pair his fruity bro could get.
Mason loves his brother, and he never really cared one way or another about his orientation. That said, when he keeps losing his lucky strap after a big game, it would start to wear on his nerves. XP

Lineart is  nateday

Color and characters are mine