There's little more exciting than a lady coming with your dick firmly entrenched in her screaming mouth. It takes me a long time to come this way, but it's worth the wait. It is critical to swallow. However, it's not necessary to have much of the cock in your mouth at the moment of ejaculation. One of the best blowjobs I ever got was where the lady slowly backed off until her lips covered only the little hole as I pumped load after load across her tonsils.
Some ladies can bring a guy up to the brink of orgasm and then stop, several times.
This produces a building sensation that can result in a most intense climax. But don't make the poor gent wait too long. Again, an experienced woman will know when the guy just can't take it any more. An interesting variation would be to have the guy tied up where the woman is completely in control of the proceedings. She can have him begging to come.