I once got rebooked into a center seat on a flight from Cleveland to Seattle. We were travelling with 3 young kids and ended up all in center seats spread over the airplane. I walked toward the back of the plane, saw my seat, and did my best not to express my horror. A very large mother and daughter had booked window/aisle and only about 6" of my center seat was showing between them.
Luckily, I have narrow hips. The D stood in the aisle while I sat down, then she did her best to wedge herself into the remaining space. I spent the next five hours pressed between them from knees to shoulders. Given that they smelled clean and were nice, I have to say, after my initial panic, it was a rather pleasant flight swaddled in warm softness. Russian weightlifters would have been torturous.
Manspreading is an attempt at social dominance, not a physical imperative. Next time you see the NFL commentators all standing around, check out the competition on who can keep their feet the farthest apart. If RuPaul can tuck his business and sit with his knees together, so can anyone.