divorced and ex asking personal questions....?

My ex husband and I were living together but separate rooms then I moved out to think about things and decide if I wanted to try to rebuild things and less than a month later after begging me not to file he sent divorce papers and started a fight dirty custody battle. Now we have been divorced over a year and living separate over two. He kept saying you should find a boyfriend even though he does not have a girlfriend. I began dating this guy a few months ago and when he found out all he does is ask personal noyb questions..."Are you going to move in with him and give me the kids?" and "when/if I had sex?". I didn't answer the second question. the first one I of course said NO so he just assumed I did have sex and lectures me like a dad would lecture a teenager...I am 37 and he's my ex so huh??? today he asked if the guy called me because he has backed off afraid of commitment and if he broke my heart and I cried. Also said "a mutual friend just let him do this?" How does a guy have that kind of control over a not that close of friend??? Everyone says it is jealousy because he wants me back but he says he wouldn't take me back and I certainly wouldn't go back but that is not part of this question.....strange isn't it?????