When I get a blowjob, I want the guy to suck me to completion. I always let the guy know when I'm getting close but I always hope he keeps working me with his mouth.
One time I got this blowjob from this guy through a gloryhole. I let him know when I got close and he kept me in his mouth. When I blew, he started choking. He choked and hacked for more than a couple minutes. Then next time I met up with him on the other side of the gloryhole, he'd only jack me with his hand. Guess I scared him.