need some advicee

so, i have this friend i know since 4th grade and we have a good connection. since class 9th, we had that soft-spot for e/o. texting each other like a LOT and flirting regularly. last month i came in a relationship with him finally but, all that he wanted to talk about was us meeting or me being his wife. quite literally. that was it. other than that he is very sweet and a total green flag but often comes around as chutpaglu type. i broke up w him because I was frustrated of the above reason. we are teens in 12th rn. I posted myself on the ig and he sent me long paragraphs about wanting to get back together. i declined obviously but lowkey, wanna get my together because i somewhat like him too. but, he's too immature for my liking. what should I do? currently we passed 11th.