Matthew Stafford's wife celebrates her birthday, as one does, by flipping off the camera & shaking her butt

Sunday was Kelly Stafford's 37th birthday, and she did what many people do to celebrate the occasion. She went out with friends, let the double middle fingers fly, and shook her butt as one does to mark another year of life.

If she wasn't married to the reigning NFL MVP, Los Angeles Rams quarterback Matthew Stafford, nobody would think twice about it. It would be typical mom of four behavior as she gets another year closer to 40.

And people think it's all fun and games being married a star football player worth millions.