Need advice on 12 & 10yo sharing a room, 12yo is starting to self explore

I have 2 step sons ages 12 & 10, and need some advice on how to address a sensitive issue with my 12 year old. They live with their father and I full time, and when I told their dad about this his response was, "I'm not ready for this". They stopped living with their mom when they were 4 & 6, and she is still having trouble seeing that they're growing up. This leaves me on first for this, and I want to address it in a way that doesn't cause my 12yo shame or guilt.Currently he and his brother share a room while we save up to move to a bigger place. One of the reasons I really wanted to do it last fall was that I know my 12yo was going to need privacy soon. Over the last month it's pretty clear that he needs that sooner rather than later, since I'm pretty sure he's started masturbating regularly. We can't really wait until we have everything set for a bigger place, because we can't move until our current lease expires. I don't care that he's exploring himself, but I am worried about three things.First, his 10yo brother is also in the room when he's doing it. I don't think his brother knows he's doing it yet, but I'm not sure what kind of psychological effects that will have on him. So I'd prefer he do it in the shower or bathroom until we can get him hus own room. This is for privacy more than anything else.Second, he's not cleaning up after himself, which is obvious from stains on the sheets and the smell. Again, I don't care if he plays with himself, but I do care he's not cleaning up after himself. I feel like this is especially important because he shares his space with his brother, so he has to deal with it as well.Finally, because he shares a room, he's been waiting for my 10yo to fall asleep, which has led to him sleeping through his alarm for school and being cranky in the morning. I want to find a way to address this so he knows playing with yourself is healthy so long as it doesn't get in the way of other things, like getting the sleep you need for school.The best way I can think of to handle it is to tell him playing with yourself is ok, but you really don't do it with other people that aren't romantic partners in the room. I was going to suggest he just do it in the shower or bathroom until we can get a bigger place, but I don't want to make him feel shame for being normal. I also want to talk to him about the importance of using a tissue when he does get his own room to help keep things a bit cleaner. Finally, I wanted to let him know masturbating is fine and healthy so long as it doesn't get in the way of the rest of life. Currently the time he's doing it makes it difficult for him to wake up on time for school.Do any parents with older kids have some advice on how to talk to him about in without making him feel bad about himself? Will the approach I'm thinking of be too harsh? I don't think it will be, but he has a very low self-esteem I don't want to damage because he's normal. via /r/Parenting https://ift.tt/2UWLHNR