I need your opinions

I met this guy genuinely interested by me, first time ever! We started going out casually and it was fun and he was just amazing. You know growing up with insecurities and never feeling enough when a great guy like that looks at and appears to be what he says he is it’s just too good to be true. So I started poking around and ask some questions and the thing is I can’t tell when he lies it disturbing sometimes. I discovered that he was in a 5 years relationship and I confronted him. Je didn’t denied it instead he confirmed and gave me al the details and started explaining how she new all about me and the “others” before. I was disgusted so I told him I did wanted to see him again but he said he was giving me time to think. After two weeks I went to talk to him I missed him really he finally admitted that he wanted to have a polygamous (in my country is legal) mariage so he was open to date many women at the same time. Even though it hurts I realized that I’m in love with him i haven’t talk to him for a long time and I miss him so much but I don’t think I can do what he want even though he was the only man that actually treated me like A human being, like a woman.