Haha, dangerous? No, not really. There's like one study that linked masturbation to prostate health but then it was refuted.

You know what happens if a man doesn't masturbate? He has wet dreams again so your body will do it for you to stay healthy.

The answer is that he should masturbate as much as he wants to. Jacking off reduces stress, helps you get to sleep and lets you concentrate on other things other than random girls asses

Glad I don't have this 'problem.'

I would have to say as often as he feels the need to. Everyone is different and has their own need time. I would be doing this every day, my hubby twice a day...so it really depends on the individual. I would wonder if the deeper question that needs to be asked is why you aren't having sex anymore and the effects it could have on the future of the relationship? Is it health or emotional? What are you doing to counteract the effects of having a sexless relationship? If you want someone to talk to you can message me at any time--I will respond!

Whether you're getting any or not, masturbate whenever you want to

As often as he wants; same for you!

There's not really any health reason not to masturbate. It can help with random arousal

As long as it doesn't cause you to miss work or family gatherings there is no such thing as too much.

My Wife Fucks Me 2 Or 3 Times A Week. And I Masturbate At Least 2 Times A Week.