If there is men on here and can explain what is going on with my ex please

Okay my ex and I have been broken up for a year and a half he has a new gf and we been on a back and forth conversation since February 2020

SO after we broke up he got into a new relationship about a week later he’s texting me he’s loves me and cares about me and wants to be with me and is full on crying on the phone, he would repeatedly say” I love you “,” I love you you know that? , “I care about you a lot”

I don’t believe him

It doesn’t make sense how u can love two people at the same time and want to be with both (I’m not with him)

Please someone(men) help me understand this 🙄

(I feel like only men will understand this )