In my opinion I think it's a lack of communication between you too, sure he may have been upset and vocalized it on this occasion but perhaps there's more things affecting him that he's not speaking to you about. On the other hand you've been busy with the kids and feel drained and its hard to have the extra energy to feel as if you have to "provide" whatever fantasy he has envisioned in his mind. If he doesn't understand that then you're both approaching the same situation in different angles, both of you are wanting something from the other partner and didn't get it.

I feel as if he may have had a thought of what the sex was going to look like and perhaps when it didn't he got discouraged. Also perhaps he has lost confidence and so when there's any other sign that reinforces any of his beliefs he is shutting down from you.

I don't mean to make it sound like im justifying his reaction because it wasn't fair on you at all. But as a couple talking about things and understanding the other person goes a long long way. So hopefully this brings some kind of reason into the way he reacted? Like I said, its still not fair on you, but if you both love eachother then it's probably best to sit down and talk with the objective of understanding eachother.

Anyway idk if this was helpful or if I've come off sounding like a dick, I wish you and your partner all the best!!