The act of
hooking up with some chick or dude. During the process of "Tearing it up", the
chick, or dude, gets so fucking horny they ferociously rip, or gently
slip, of their clothes and/or undergarments.(hopefully).
Example
1: Guy
1:Dude! Last night i got that chick so horny, we started tearing it up!
Guy 2: She let you in on her cuddy?
Guy
1: Hell yeah!
Example 2:
Girl
1: I was so wasted last night girl!
Girl 2: I heard you and that guy you met last night at the club were tearing it up at your dorm!
Girl
1: Yeah, i hope he used a condom.