I can understand that part, but I would also never just start jerking it in the time it took my partner to get up and get a blanket. Like, what? Wait a bit if you're gonna be self-conscious, horndog!

That said, it's not cool for him to take his embarassment out on you and start getting blamey. His embarassment is his own problem.

And maybe it would be a good idea to consider separate rooms? You don't necessarily need to live in separate apartments. Me and my partner love each other a lot, but we also both need our own space at times. Having 2 beds in 2 separate rooms has been great for us. A lot of the time we do sleep in the same room or cuddle, but when we're needing alone-time for whatever reason, it's great having separate spaces.