Why does my submissive boyfriend get quiet when I tell him I'm horny via text?

Is my submissive boyfriend secretly gay, just not into women, me?

Has he watched so much kinky porn/done mostly kinky shit, that all he's used to is not reciprocate or "participate"?

Things he's said that make me wonder:

- vanilla porn never did it for me

-you can get me so deep into subspace that I'd suck a dick for you - I know this doesn't automatically mean he's gay, but uts delivery made me remember it.

-only seems interested in feet, though always female <-- IS THIS MY ANSWER?

- sent a video of me masterbating, got a thumbs up

-texted him I was horny... participated, but his attention was divided, when it wasnt divided before mentioning I was horny.