Brittany Mahomes did not go to war against "mom butt" roughly a year and a half ago just to sit at home on Friday night during the offseason. Not when she could be spending it at the Stagecoach music festival. The 30-year-old didn’t face that battle head on to attend the country music festival quietly either. Nobody would. That's why when she was presented with an opportunity to dress up as a cowgirl and post it on social media, she took it, and you can't blame her. As Brittany has explained before, life as an NFL WAG who turned that into an appearance on a Sports Illustrated Swimsuit cover isn't as easy as it sounds. There's a lot that goes into being the wife of Patrick Mahomes . "I think being the significant other to an NFL player is an incredibly hard role, and we take on a lot of important stuff behind the scenes that people don’t get to see," Brittany told Sports Illustrated in February. "We also get to enjoy life and do things that we love, too." ZERO BS. JUST DAKICH.…