Why would a man typically eavesdrop on your conversations?

Anonymous
To put it in some context, he used to playfully tease me, I would catch him staring, watch me when I was talking to other men, and he even took my hand and stroked it looking into my eyes in front of the girl he has been dating for a month but she did not see. Then he was cruel to me when I told him to keep his distance given this and now he broadly ignores me but I catch him looking at me when I speak to others in proximity to him and he eavesdrops on my conversations with others.
Why would a man typically eavesdrop on your conversations?
2 Opinion