Phenomenon occurring to individuals that are roughly thirty pounds or more overweight.
Due to the increased size of the originator’s gluteus maximus, expelled gas from the anal opening is briefly trapped within the confines of the enlarged anal cleavage. Instead of producing that flatulent sound of which we are all familiar, the gas moves and eventually escapes as one big bubble. This causes the cheeks to slam together violently once the pressure is relieved and results in a distinctive WHAP! sound.
“Her snoring was enough to deal with at night, but once she started fartclapping in her sleep it was time for her to go.”