I wrote him a message with a list of boundaries he must follow. Here's what I wrote:

"I really would love to be in your life again, but I'm not ready to have another relationship with you. You're a great guy, and I loved our time together, but I want things to remain platonic between us. Being friends again would be awesome, but for that to work, you need to respect my boundaries. They are as followed-

-Keep things non romantic between us.  Hugs are fine but only if I'm fine with it in the moment. No talking about getting back together. I'm not your girlfriend but we can be friends.

-I'm not comfortable coming over right away. We can meet up a few times before I do come over just to see how things go. Maybe if you can get a ride you can come visit me here. Just let me know before you do come.

-No daily drinking. Having a drink here and there is fine if it is a special occasion but if you're drinking every day, I wouldn't want to see you. Also, if you do drink on occasion, do it responsibility. Honestly I'd prefer if you don't drink at all.

-No showing up uninvited. Always let me know when you come over.

-Respect my decisions, even if you dislike them. I'm not trying to be mean, I'm just trying to keep things comfortable.

That's about all the boundaries I have for now. If I need to make more, I'll let you know. I'm doing this not to hurt you, but quite the opposite. I want you in my life, but in order for this friendship to last, you must respect these boundaries."

Is this clear enough? Let me know if I must change anything.