The men who become paranoid or bitter about dating women after dating a horrible woman may have given a lot of themselves to those relationships.
These were women that they may have put a lot of their trust in. That trust was betrayed in some fashion by the horrible woman and the men become paranoid and bitter.
People respond to a sense of betrayal in different ways.
People don’t always fall in love with each other at the same time despite how much one party may want that.
If you haven’t been dating this guy for long and you already know that you love him, he may get to that point as well. He is a unique individual that will respond to you in his own unique way.