Is he trying to forget me ?

I’m in this complicated position..
I was in a party last summer where I met an old friend of my ex, they were never best friends, more like old class mates. I have met him couple of times in my life through my ex,so I knew him a little bit, but not very much. I never paid a special interest to him before.
In this party we chatted a little bit and he told me he was going to move to a new house and it would be a lot of work on the moving day. I in my kindness offered him my assistance.

2 weeks later I showed up early at his place and help him moving, I noticed that he was very flirty that day. In the end of the day when everything was done he opens a bottle of wine and ask if I want to have a drink with him and he would order some food.
I agreed as I was starting to like him. We had more wine, and I stayed there the whole evening, we got very well along, he was smart, funny and good looking. We started kissing and I ended up spending the night with him.

After this night I didn’t see him for a month, because I was away . But we did keep in a little bit touch through some texting.
When I was back he quickly asked if we shouldn’t meet for a dinner together. I said of course yes. We arranged a nice evening where we made dinner together and had a very romantic evening , and I stayed again at his place for the night. When I was leaving the next day he asked if I wanted to come over again the next weekend and have dinner together , I agreed as I was having a wonderful time with him and I realized I was in love..
The next weekend was the same I had a wonderful night with him, and when I went home he even texted me on the way to thank me for a wonderful evening and how great time he was having with me.

Few days later he tells me that he is inviting few friends over for a party and he really want me to come.

In the party I did not talk much to him , but we danced a little bit and had a good time. When the last guest left I assumed that I would stay over but he acted weirdly like he was expecting me to leave to.

I asked him if it was okay I would stay for the night, he looked at the watch and said, of course its late, you can sleep on the couch … I was like what!
I walked to him put my arms around him and was going to kiss him but he turned away and said “We should not do this ” and went to his bedroom. I was in shock.
I went to the couch but didn’t really want to stay , I felt unwelcome.

The next morning I just wanted to get away. When we woke up I said I should better get going home, and he said yes, but gave me a good bye hug.

Now it’s 2 months from this night, I’m still in love with him, still confused and don’t understand what happened. I tried to text him, he replies but it is different… No offers about having a nice evening together or hanging out. I really don’t understand what happened. I think it has something to do with my ex, as he don’t want to spoil their friendship by dating me.

Is he trying to forget me ? What did he mean with this “we should not be doing this”?