Why would my ex boyfriend tell his friend that I have problems behind my back?

A few years ago when I was dating my ex boyfriend, I oversaw his text to his friend he texted him saying how I am and my ex said she has many problems. Why would he say that while being with me at the same? Saying this behind my back was odd. What problems you think you think he meant to his friend? Like mental problems? If he chose to date me and love me, why would he talk bad because of me behind my back? He ended up dumping me then regretted it then we got back together then broke up again. What are your thoughts and why would he think that I had problems?

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12 h
And he was also autistic like me!
Why would my ex boyfriend tell his friend that I have problems behind my back?
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