Cheated on me with his ex/ 16 years age difference?

I met this guy over a year ago and we became friends and since then we were speaking but mostly on whatsapp cause I live in a different country. This 22year old guy had a relationship with a 38years old woman which he used for her money appearantly. Few months ago we met again and officially got in a relationship where he met my family and I am his. At the end of my stay on my last day to be exact (2,5months) he cheated on me with his ex and now they’re back together and I don’t get it. He always told me that this woman was manipulative, jealous and treated him bad so I don’t get why he hurt me acting like this although everything seemed to be great, the time we spent, our 2month travel and our relationship. by the way he is a very mature guy so yh
Cheated on me with his ex/ 16 years age difference?
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