Yeah, at my school, both in junior high and high school, if you didn't shower after gym, most guys would rib you for it. Most common comments:

"Rule #1 of puberty: Shower every day."
"What? Afraid we'll see your inch worm?" (Stack of dimes and little friend, emphasizing "little", also accepted.)
"Afraid you'll pop a boner?" (Especially effective when dealing with kids with a reputation for homophobia.)