1. a) Laughing Out Loud While I Poop
b) Laughing Out Loud While I Pee
2. The act of laughing within an excessive audible range, whilst defecating and/or urinating.
Person 1: That post you shared with me on Facebook was so hilarious!
Person 2: You saw it when you went to the bathroom?
Person 1: I was LOLWIPing!
Person 2: I pray you washed your hands afterward...