Advice.....😳

My ex has been texting and calling me. He said that he is still in love with me which I don't believe and I don't care. He broke up with me 7yrs ago(he stopped talking to me after we had sex for the first time and never said why.) before he got married he asked me to leave with him to another State. I never answer because I though he was crazy and obviously I didn't have feelings for him anymore. Now he called me to tell me that his wife is pregnant and he said: "I wish you were my wife and you were the one who is pregnant because I've always loved you and I know that we will very happy together." he text and call me from different numbers when I don't answer him. The truth is that I would never be with a married man, I don't feel attracted to them. I know his wife because I used to go to the same church as her. I never talked to her. Sometimes I feel that she deserve to know what her husband is trying to do behind her back but I don't want to break her heart. Can someone give me an advise?