Why would a man that is in a committed relationship and tell his partner daily that he loves her and wants her but yet was entertaining another woman?

Updates
6 mo
Oh. I should have worded it differently. It's not 1 women. It's multiple.. like he has to have the attention.
Updates
6 mo
And it's only over the phone. Social media that I am aware of for now. But you guys... Tell me this... He says he's not a very sexual person that's why we barely have sex. He says it's not me and there is nothing wrong with me. That it's him. But watches porn also
Why would a man that is in a committed relationship and tell his partner daily that he loves her and wants her but yet was entertaining another woman?
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