A Morning After Tee Shirt is when you where the tee shirt of the last person you had sexual intercourse with the next day to work or school.
Girl 1: Ew. Why are you wearing that ugly boys shirt?

Girl 2: No. It's my Morning After Tee Shirt from Dan.

Girl 1: Oh. Makes more sense now.
by Icey0123 March 16, 2010
Get the Morning After Tee Shirt mug.
A dude's button up shirt commonly put on by a girl when she wakes up the morning after
Damn she looks even hotter in the morning after shirt than she did last night.
by Baby Octane October 10, 2017
Get the morning after shirt mug.