Grab the lube that you located at the beginning of this tease and apply it generously to his cock.
As you do so, say, “Here comes the really fun part. Well, for me anyway. I’m going to subject you to a treatment that I like to call ‘Finding the edge.’ How it works is, I’m going to stroke your lovely penis almost to the point of cumming. When you feel like you’re getting close to the edge, you need to tell me right away, do you promise?"
Don’t continue until he gives you his word that he will alert you when he thinks he’s almost ready to cum.