Problem is, even if it happens, it doesn't suit his character how it is protraied. There is not a single deciision in the whole game that is based on HIS wishes, his inclinations, his needs. IN all the reasonings (and they are given to us extensively and repeated again and again in the text) given for his choices the husband puts the wife, her wellbeing, her wishes first or rather: there is nothing else at all. If he thinks about going to the shoot or not, both alternatives are motivated by her: would he give her more confidence (how often will I read this word again?) or will he disturb her? It's not about him, it's never about him. In one word: he is a fanboy, not a lover (and that's what I meant by "weak" some time ago).
Now you could say that's not a problem, on the contrary, that it fits an NTS narrative (but not the "stag" variant, sorry guys). But even his role as a voyeur during the shoot is affected by that: he is there not for an erotic experience if you read his thoughts carefully, but to admire her success to wish for her success and sit there with an open mouth staring at some kind or goddess. That he gets a hard-on is an afterthought right at the end and he seems rather embarrassed. He is not horny really, he has no dirty thoughts, no straight-forward sexual desires a vouyeur in the real sense would have. It's rather asexual, innocent fandom towards his own wife. And this can become a probllem for the character-development even if you don't identify with him as a player (which I don't). Because then there is no (or at least: less) erotic tension, no possessive claim or strong desire which feels provoked. You also could say: nothing on him is a pervert. But if it isn't - why should he let himself get being cucked then?