Mappsofcambridge's definitions
When someone is in "decent" shape while unofficially seeing someone and once the relationship becomes official they gain a shit ton of weight. The other person is then trapped in this new relationship with the newly fat fatty.
Omg did you see how Mikah fat-trapped Sarah into that relationship. The most brutal fat-trapping I have ever seen. Once they started dating he gained 70lbs!!
by Mappsofcambridge September 10, 2016
Get the Fat-trapping mug.