Stay fwb or no?

Ok so like me and 3 other people are super close friends since middle school we are now college students. (2 guys and 2 girls) so two of my friends are in relationships, not with each other and my other friend just got out of a relationship months ago. Me and him randomly hooked up one drunken night but then hooked up 3 more times after that. We aren't thinking of making it into something just fwb. But he's been really clingy with me and his ex messaged him so now he's thinking about getting back with her. Should I still be fwb with him still or stop since he's considering on going back to her. I'm not a home wrecker so I told him if they even slightly talk about getting back together he needs to let me know Bc then we strictly just go back to being friends. He said he's unsure if she brings it up if he does want to date her again. We also hang out all the time and he tries to hold my hand but I avoid close things like sleeping over or kissing goodbye because then I don't want to get attached in a romantic way. Sorry I'm all over the place with this but I don't know what to do and please don't be rude we are both adults and no one is cheating and I don't plan to have him cheat