An Instagram model famous for her big booty wants to make them bigger ... but Gracie Bon's not talking about her cheeks, she's talking about airplane seats.
Gracie's petitioning the airlines to expand their seating situations ... she says she's having trouble getting settled for takeoff, even when she's flying first class.
The busty poser lays out her air travel problems in an informative video -- a PSA, if you will -- demonstrating how her butt is way too big for a traditional plane seat.
Seems like legroom's not the big sticking point here ... Gracie either wants the seats to be wider, or deeper. She's still able to buckle, courtesy of a seatbelt extender.
Gracie says it's on the airlines to accommodate "big girls like me," and proudly adds ... "It's not my fault to have an ass this big."
The whole thing is pretty ridiculous to lots of folks watching Gracie's video plea -- several comments claim it actually is her fault she has such a big booty, accusing her of surgically doctoring her look.
Fact is ... Gracie's the outlier here. If everyone had a booty as big as hers, airplane seats would be wider -- but most people don't, which explains why she has 4.5 million followers.