I've done this a few times. The first was when I was playing a bondage session with my first boyfriend. He had tied my arms to the bed and was really getting into it. Stroking me, sucking me, then fucking me until he came. I was desperate to cum and begging him to finish me off. So he rolled my legs up over my head and wanked me off. I exploded all the built up cum all over my face hair and neck. It was really filthy but I enjoyed it a lot.