so, every time I'm sitting with a guy, ( not every time, but I've seen it a lot) he will lean back a bit, so his butt is off the chair, grab onto his pants/shorts at the knee area, and pull a bit. are you just re-adjusting...or are you covering up a hrd on? idk, I'm just curious Because I've never felt the need to do that. haha
We pull from the knee area towards the groin in order to place more pant material near the groin area. With more pant material near the groin area, there is less pant tension near the groin, with less pant tension near the groin there is more space for the groin, thus we are more comfortable. It is never comfortable to have material tightly stretched near our groin area because it is uncomfortable, and it may reveal our limp genitalia pressed against it. It is not an effort to hide an erection. For that there are other techniques.
Its just uncomfortable when you sit down and the pants ride up, I'm sure its the same way for girls too. He is not covering a hard on, he is just untangling stuff lol. I also do it when my pants aren't covering my shins/ankles...its cold and annoying lol
Sometimes if I sit leaning back too long I will slide forward in my boxers/jeans and then have to do that because like the other answerer said stuff down there gets pushed to one side or tangled or something and it's uncomfortable.