1. When a (usually) young man masturbates or receives a hand job, and ejaculates all over his own shirt. He then has to self consciously walk around with a cum stain on his shirt, unless he was at home or had the foresight to bring an extra shirt with him.

2. Sloppily and shamelessly enjoying oneself without consideration for appearance or the feelings of others. Can be male or female

cum on the shirt (n) is another version of this saying
bob went to sally's house after school. she didn't want to blow him, so she tugged him off and he came on his shirt. Then he rode the bus home and felt hella awkward, since he didn't have a coat.

Suzy was being such a drunk ass at that party last night, she definitely came on her shirt.
by Reggie Jefferson November 20, 2012
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