Would you take back an ex who's been with someone else?

Hey girls.

I've always wondered this from a different perspective, so me and my ex have been together for 4 years. We split up last year in August (it was very much needed our relationship was so toxic) I'd say 2 months after we started dating other people, and I dated someone and then that ended in January 2017. He was with his ex girlfriend until may 2017 and we've recently started speaking again we haven't spoke or made contact for 8 months so everything's all new again the only thing though because I've already stepped forward I'm scared I'm going backwards and he keep can't get over the fact I was with someone else (previous to that he was the only person I slept with) so he's acting weird but I don't understand .. he's been with someone else too?

I'm just wondering can ex's rekindle after such a toxic relationship and almost a year apart?