I have ejaculation while doing straddle split,straddle lever support,pencake stretch,L seat,hanging leg raise and some other exercises.Have you ever heard about this problem?What can I do to prevent from having it?

I have ejaculation while doing straddle split,straddle lever support,pencake stretch,L seat,hanging leg raise and some other exercises.Have you ever heard about this problem?What can I do to prevent from having it?

Tight underpants.