People saying it's a porn or a submissive thing are insane
It's because he's fixed on it.
In real life sex people do all sorts of things during oral sex etc - eyes down, eyes closed, not always looking directly into the eyes of the person they're doing it on. They should be "allowed" those variations, it's natural behaviour. The recipient should just be glad they're receiving it and not staging it, as such.
The fact he's fixated on this thing, and trying to stage manage it - makes me feel like he had a strong idea in his head of how it should be (based on porn, in which they almost always do the eye contact thing when giving oral sex) and it's a "recreation" of porn scenes, rather than a natural, varied, go with the flow thing.
If the op doesn't naturally look a guy directly in the eye when performing os or when he climaxes, that's her "style", end of .... And he should accept that, he sounds like he's trying to turn her into a performer. The OS is a performance. Like porn.
I, for one, think it's likely to be porn based.
So many porn sick men around.