Getting semi hard while hanging ots

Hi guys, when I’m hanging OTS I always get close to semi erect. When hanging BTC this is never going to happen.

Has anybody the same experience?

Yes I get that too, I think it has something to do with the penis being in it’s natural erect position. Also because it’s one of the less used angles, it’s new for it. My BC muscle seems to clinch no matter how long I try to relax. I usually just keep it on until the slight semi goes away.