I give a lot of blowjobs fully dressed for horny men in a hurry. I only need his cock, he only needs my mouth. When we're done he stuffs his cock back in his pants, I lick the last traces of his cum from my lips and we go our separate ways.
I cum fast when a guy devours my hard little cock like that. And during no part of this would I have been soft. Most definitely would have been hard and seeping before pulling it out knowing what was coming.