Why does my ex want to hook up suddenly?

Hey guys ! So this guy and I were together for 5 months.. we mutually per say broke up a month ago , I was upset a bit of course and all. We stopped talking since the breakup only for work stuff or other things that’s it. Ever since I’ve been working on myself a lot like going to the gym I’ve become a gym junkie and just having the best time of my life with friends and family. we still got each other on a social media network and he’s seen everything I do lol.. not sure if it was because of the “holiday spirit “ or what not lol but he asked me to go on a road trip with him I’m not sure why , well I didn’t end up going with him at all. Ever since he’s been more talkative with me and We’ve been good friends I could say left that rough patch aside and we are now good friends we’ve been talking about everything together... well not only sex but we’ve hung out and of course you guessed it sex... face palm. I’m honestly not hoping or seeing this as a reconciliation but why? Now that I’m doing better I guess you could say he wants to share personal stuff with me and take road trips with him and of course hook up and be there for me..
Why does my ex want to hook up suddenly?
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