Quoting Ashley Yarber:" Almost all, if not all, men masturbate. My boyfriend is a man. This is kinda obvious. It bothers me, ... [snip!] ... the day. I feel like he has two sex lives. One, with himself. And ours, which is steadily decreasing. It's so upsetting. :/"
In my house p**n is a big no no for religious and non religious reasons.
Masturbation is ok as long as we are masturbating about only eachother.
Ofcourse if it became something that he became obsessed with and he did it more then we had sex, that would be an issue.
Try and join in on it if you know he's doing it maybe go and "help" him. haha.
About the shower thing when you were in there with him, I might be a bit weirded out honestly and I'd talk to him about atleast letting me know before he goes and does that.
OP, perhaps your SO wants you in the room to hear/ see you -- I can understand you being a little weirded out that he wasn't telling you what he was doing in there but if you know now and he still calls you in the bathroom, maybe he's trying to hint at something!! If you're not interested, let him know right off the bat... and if you are feeling up to it, get in that shower! You said you're not getting much action and he's masturbating more... are you talking to him about why that might be?
As far as the toy situation... get a non-phallic shaped vibrator such as a bullet, one that's waterproof... bring it in the shower and use it together. He will totally change his mind about you using toys on yourself.