I’m okay with it but...

So my boyfriends brother asked me if he could move in because my boyfriends mom treats her kids not so well. I told him we’d have to discuss it. He said hell help clean and help with bills. He’s graduating in about two weeks and already has a job. There are only two problems. That means we have to wait for a baby. He also wets the bed. He is 18 and wets the bed. He wont go get help but I don’t wanna hurt his feelings, but I don’t want my house smelling like pee all the time like my boyfriends mom. He usually cleans his own mess if he does but it still stinks. I don’t want to have a baby if I have to clean and make sure the house doesn’t stink. I don’t wanna be mean. My boyfriend wont say anything either cuz he doesn’t wanna upset him. I don’t know what to do what would you ladies do?