Why are men so confusing and act this way?

Early last fall, I started to see this guy. He was upfront front from the get go that he does not want anything serious and I was alright with that. His words did not match his actions. When we were together he was very affectionate, caring, respectful, made sure all of my "needs" were met, wanted to cuddle and talk after . Always had to be holding me when we were sleeping and didn't want me to leave in the morning. Fast forward a little...I told him that I started to have feelings for him and he said that he is just not ready and where he is at this time in his life, he will not be able to give me everything I deserved. So I ended up casually dating this other guy...and the commitment-phobe wanted to get together. Told him about this other guy and said that he needs to make a decision if he wants to be with me because I don't juggle guys. He wished me luck with my new relationship. Now all of a sudden he is contacting me more and it seems like he now wants to take that chance with me. I like my new guy too much to drop him for this guy. But why now all of a sudden he seems interested to want to turn our FWB situation into a relationship now that he knows that I am getting serious with a guy? I gave him a couple of chances to be with me and he didn't bite...but now it seems like he is competing for my attention and affection???? Don't get guys, lol!!!