No legs after masturbation

So, when I usually masturbate it takes me between 20 sec to 5 minutes depending on how aroused I am but sometimes it takes more than 20 minutes. The last time I masturbated more than 20 minutes, when I stopped and tried to stand up from my chair I fell on the floor. Like, I falled on my knees, damn, I felt NOTHING. I wasn't sure what exactly happened cause I wasn'able to step right with my feet so I slammed my knee in the floor with full force and NOTHING, 0 pain. After like 2 minutes my legs got the sting feeling and could barely move. I lied on the bed and after 2 more minutes I was ok. TL;DR I ejaculated, stood up and fell from the chair, no pain, couldn't walk for 5 minutes

IIN?