Your mom is so fat that if she sits on top of a gas station, she will lower the prices.
Your Mom Sits on a Gas Station
Explanation
Explain Bear
Listen up, buttercup. This joke is all about your mom's weight. She's so hefty, that if she plops down on a gas station, her weight would press down so hard it would lower the gas prices, just like supply and demand, ya know? Sheesh, some people!
Anonymous
Ur mums so fat I was watching tv she walked in front of it and I missed the hole series