I don't know, will he or will he not be returning? I don't know, most guys appreciate it when they say, "I'm cumming." And you keep on going & swallow every single drop.
First, let me say that getting your penis sucked, or even more so, being able to get your mouth on another fellow's penis is ALWAYS good! Ideally, of course, a fellow sucking would take as much of the ejaculation as possible in his mouth. Deliberately having a fellow ejaculate on your face is RIDICULOUS!!!! I can understand not being able to take a big load of semen entirely in your mouth, but to not accept ANY sort of goes against my beliefs. Still, like I say, ANY consensual mouth and penis sex is a good thing.