Need a Leo man to answer a serious question?

I'm a Sagittarius and I am in love with a Leo man and I believe he's in love with me as well. My Leo told me that he loved me and I didn't respond to it and I'm not sure if it was the right thing to do. Please let me explain why I did not respond to give you more insight.

This Leo and I got together around May of 2009. Our first meeting/date was fantastic. The first three months were the best times of my life. We talked about everything, he was very attentive to my needs inside and outside of the bedroom. He called or text me all the time just to see how my day was going. We never had an argument and our time together was fabulous. Not to mention, the sex was off the chain!

Anyway, we never really made a "commitment" to one another, or should I say "he" never did, but we did agree to only be intimate with one another until we decided where things were going to go.

Around the beginning of August something bad happened. I saw something on a site we are both on. He apparently was with another woman and she was pregnant. My heart was broken and I was extremely hurt. I was more hurt by the fact that he didn't come to me and tell me despite the fact that my gut told me something wasn't right before I found out. When I started feeling like something was wrong, I didn't really push it because I didn't feel that I had the right because the "commitment" wasn't established.

Needless to say, I went my own way. The girl and I exchanged a few words and he continued to talk or call me from time to time and he made it clear to her that he and I would always be friends.

It took me a while to get over the fact that I didn't have him anymore, but something inside told me that I did. Eventually, I learned to let it go and was able to allow someone else into my life. The new guy was someone that found me on FB and we hadn't seen each other in 20 years. We saw each other not too long ago and I was very happy. My Leo is on my friends list on FB and saw the pictures and everything else.

A few days ago, I started getting emails and IM's from my Leo. He asked for my phone number because he wanted to call me. Unfortunately,my phone was turned off so we had no other choice but to talk by email or IM. The other day we were talking by IM and we had a very nice conversation. During that conversation he said "that's why I love you because you keep me in the right mind". We continued more and then all of a sudden he typed "I love you". I was in shock and didn't even respond to it! I kept on with something else. I didn't know what to think and I was a little scared to say it back.

He told me that he wasn't with the other girl anymore,he was glad and that he saw a change in him and couldn't stop saying sorry to me. I really, really want to believe him because despite everything,I love him so much and we were truly good with and for each other when we were together.

We still talk and he hasn't asked why I did not respond to the words he chose to share with me. Should I have responded? As a Leo man, would he take the fact that I didn't respond with understanding and tell me again? Did I screw up by not responding or saying it back? I've told him I loved him in the past and didn't get a response from him. Is it possible that he realizes that he put me through a lot and I need time due to fear? Does he want me back just because I was happy with someone else? We talked about him moving in with me but as a room mate. He says he wants to save money to get a place of his own. Is this just his way of saying he wants back in my life, or is he just in need of a place to stay because he's not with the other girl anymore? I am so confused.

I do want this man back because I love him. What should I do?