Why would my ex text me on WhatsApp that he miss me and wants me back and also when I back searched through a friend, why he was in bumble too?

Should I go back to him?
So we were together for 2 years in a relationship where he had proposed me on 3rd date. Suddenly he uncommitted to me after 1.5 years of our relationship and stopped having sex with me too. And he never asked me out except for video call talks everyday and night despite in same city. Whenever I asked him to take a day off and going out on dates or together, be denied everytime. And Feb Valentine's Day he said yes and on that day he tried to breakup with me but when I cried he withdrew it. March he was on bumble despite us in relationship and I saw the app in his phone and he used to lock and change his password often and tell me but since 6 months he didn't once I saw at 1am an unknown insta girl sending him request, April he was double dating, I caught him red handed by copy pasting a number when he went to washroom, to my WhatsApp, when I saw 1 hour calls with some girl living nearby city and when I asked the girl, she said that she blocked him etc and that he was seeing her and asked her for sex. Then she and me both felt bad coz he was playing us and she didn't know of me. She immediately scolded him and blocked him. For me, I was too hurt I said this incident to his 2 friends and he was trying to explain that he was just talking and nothing serious but how can it be everyday for 1-2 months? That too 1-2 hour long? With another nearby city girl.. and he said me to text that girl to assure her that he was not double dating so that his reputation is saved in the community - that girl and he was from same community caste, but I felt he cheated, so I blocked him everywhere.
Why would my ex text me on WhatsApp that he miss me and wants me back and also when I back searched through a friend, why he was in bumble too?
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