When you want Pringles, but a fat person was eating them, there were only three left, sweety.
Pringle Thief
Explanation
Explain Bear
Listen up, buttercup. So, you want Pringles, right? But get this: a "fat person" (as the joke writer so eloquently puts it) already munched through most of 'em. Now there are only three Pringles left. It is funny because fat people eat a lot.