I separated from my exP in September for a number of different reasons. Most obvious problem was his drinking and usual aggression (not physical but shouting) when he got drunk. It was a mutual, inevitable decision due to the circumstances we were in. I was heartbroken for things to end, and he was too. I was a mess for about a week but have been using the time to address my own MH issues, have landed a better job, and reconnected with old friends. Despite all this, I still very much miss and love (in love with) my exP.
We are in constant contact via texting and calls, and both of us have said at various points it doesn't help us move on (I've got a suspicion neither of us wants to). He has commented in the last few weeks about how much he misses me, how things aren't as enjoyable without me around, that he loves me, that he wanted to treat me better and how much of a good person I was to him - he said I was the perfect partner and he has to live with the fact he ruined our relationship and it devastates him. I heard through a friend of ours that he was very down about three weeks ago and said "I'll never find anyone like her, I've fucked it and she's gone". But, things aren't perfect, things still crop up from the past where I get angry and he gets defensive (and then apologises). We've met up about 7 times in the past 2 months, 4 of which I ended up staying the night (cuddling but not sex)
I am aware that he's in counselling and therapy for his problems. He has been telling me for some time that he is avoiding situations with alcohol, and has thrown himself into his career, where he is excelling. I feel so proud of him, but it makes me sad he's no longer my DP 
Anyway, last night we attended the same event, where alcohol was readily available. We didn't actually go together or have mutual friends there, but he text me as I got there telling me where he was and that we should get seats next to him and his friends. I was apprehensive at first in case he had been drinking but when I got to him, he was completely sober. We were just laughing and catching up and he keeps saying "It's so good to see you" "I've missed you". One of his friends asked him if he wanted a pint and he accepted and I had one too. We weren't drunk. But as the event moved on, my friend commented that we were being very "couplely" - there was a lot of hugging, and flirting and messing around. He kissed me on the cheek, the head and my hand a lot in front of everyone. When I said I had to go for the train he said we should get on the train he was getting - it was packed and we ended up in different carriages, but he text me asking where I was and whether I would be up for a "proper catch up" sometime this week, we could go for a meal. He's text this morning again asking when I'm free and that he had a good night.
AIBU to get my hopes up of a reconciliation with him? i am aware that it's an uphill battle and we still need to work on ourselves, but my friend who was with us last night said we're heading for a reunion