<human>: Can you give me the gist of the text in a nutshell?

He broke up with me in early August, and it's been a tough month for the both of us.

Recently, his roommate abruptly decided to move out and my ex was left to scramble to find a roommate. A friend of a friend was looking for a place, and he mentioned he was looking for a new roommate. 

Problem is, she's a girl.

When he told me, he reassured me nothing is going to happen. He doesn't want any sort of awkward encounters with her and doesn't want to run the risk of losing another roommate.

I kind of told him I was uncomfortable with this decision and told him "things happen" in those kind of situations. He doesn't believe he'd do anything like that, but I'm worried he may be tempted in the future.

I know we broke up, but I still hold a little bit of hope that we may get back together. And I'm scared that if he's living with another girl, he'll start hooking up with her and our window of opportunity to salvage our relationship will be gone. 

Should I be more honest with him, or simply get over our break-up and hope he doesn't do anything stupid?
<bot>: Ex-boyfriend is getting a roommmate, and I'm scared they'll hook up and he'll forget me.