Personally I like option number two. Even if he pulls back, she can still be stroking and aiming. I'd rather not see him touch himself when she can do it.
For a fantastic tutorial on a closed mouth, woman doing the work cumshot please watch head case 2. The scene with Riley Shy and the scene with Cassie Young are fantastic. Both have wonderful facial expressions, and genuinely look like they're enjoying themselves.
That's infinitely better than some overworked jackass meatpuppet flogging his dick to death for five minutes while a disinterested whore sits there with he mouth open. Might as well jerk off into a birdbath. I don't watch porn to see a guy jerk off, I watch to enjoy a hot woman ENGAGING in sex acts.
I hope sooner or later the male jerkoff into the open "bird mouth" goes the way of the creepy man cumming face shot that plagued porn in the 80's and early 90's.