Any kind of sexual method, technique or activity that you are involved in, so long as it occurs on your roommate's futon without his/her prior knowledge and results in semipermanent evidence of said activity on said futon. (Whether accidental or not.)

This term is especially viable when used as though it were a safe-sex method.

A portmanteau of carpe diem, a Latin phrase that means “Seize the Day!” and DM, which stands for Direct Messages. This word means seizing the day via DMs.