I Don't Want My Brother To Have A Girlfriend

I have custody of my brother who is 16. He lives with me and my boyfriend because our mom is a piece of shit. He's been talking to this girl and really wants to ask her out, but I don't think he's emotional ready for a girlfriend. He's still working out his sexual assault in therapy. I don't want to control him, but as his guardian I think I should be putting some input to keep him safe. He had a suicide attempt a few months ago and he is just in a really fragile state. I don't think he needs a girlfriend rn.