I have a 1 year old grate dan and a beagle rot mix.?

i have a 3 year old lil brother and my beagle rot mix is good with kids. but my grate dane is a big dog and if my lil bother tries to bet him the dog will lean on him and knock him down or if my brother is in the way the dog will try to jump other him i can walk my dog yet because he is not neutered and he is always horny. my dogs like to tare up stuff even though he has chew toys we are planed to get him neutered in a couple day i need this and any other advice you can give me.