So reddit, how do you last longer?

Simple post: At a party last night, found a girl and we hit it off.

Not my best, just couldn't keep from doing it. I've heard that flexing any muscle will drain the blood from your junk and that can slow it down, but whenever I've tried it doesn't seem to work. Tried to flex abs, also flexed legs and it worked better but not much.

So reddit, how do you last longer?