When a male wears a undersized underarmour shirt to enhance his dilusional muscular physique
your fat stop wearing those titty tee shirts.
A T-shirt that a girl wears that shows lots of cleavage. Usually gives you a boner and you cannot stop looking.
I was on Skype with Megan and she had on a Titty Tee. It was so hot that it gave me a giant boner and I could not stop looking.