To be struck with an incessant laughing/giggle fit that keeps going on and on at inconvenient times, rendering you fucked because now you look weird.
Person 1: *sitting in a classroom which is currently silent then happens to think of a funny line from Pineapple Express that strikes a chord* AhahahahahahahahaHAHAHAbuah! *clutching stomach, tears streaming down face, trying to be quiet but failing*
Person 2: That man....is suffering a GiggleFuck.