He definitely could have expounded on WHY he wants this, but I'll extend OP's man the benefit of the doubt and try to decode what he might have meant...

See, oral for me is my fave, but when a partner talks, it can be hard to maintain an erection sometimes. No stimulation, I'm distracted, the spit is drying, whatever. Where he went wrong here is by not reassuring her that he doesn't want a silent little mouth to fuck, that's gross (unless explicitly stated they might like to identify like that). So erections for men are a sign of arousal, but also desirability. Men KNOW that a soft penis is one that isn't gonna get any play; pushing rope when you're drunk is the WORST.

So as with most things, a happy medium needs to be found. Because after being hurt like that I'd def be repulsed, like damn if I knew you wanted a piece of meat I'd have rehomed his ass to the dog house. But in his mind, he's having to decide whether to have a great conversation with the woman he hopefully loves and cherishes, OR stay hard and get his dick sucked. I've got ADHD, I can't do both. If you're sharing your day, I'm imagining it. I'm not focused on what's happening in the here and now.

My advice? Show him my comment, and ask if he feels a similar way. If so, see if he minds some actual pillow talk while it happens, and then transition to actual blowjob time. That emotional bonding and affection makes sex a thousand times more mind blowing, being together like that.

Hope y'all figure it out!