He asked if you were going to that specific party because he was just curious.
He did tell you that he would be going with his work buddies.
Interpreting his behavior in this instance would most likely suggest that he wanted to get a better idea of who he would know at the party.
In essence, he may have been trying to ascertain who else he would be able to comfortably approach and socialize with at the party besides his work buddies and possibly the party organizers.
It is unlikely he asked you about whether you were going to the party because he wanted to become closer friends or something more than that.
Again, he most likely did it in order to get a better idea of who would be there that he would know.
The sporadic communication that you have had with him since then through social media is just normal chatting to him.
He may be completely oblivious to the notion that he is sending you mixed signals.
He is repetitively liking your photos and commenting on your stories on social media because he feels free and relieved.
He no longer has to worry about his fiancee.
He is free to engage with whoever he wants online.
Again, as suggested in our earlier discussion, you are most likely not the only one that he is doing this to.
You did mention that he has become more active on social media of late.
He is most likely spending a good amount of this time on the social media of other girls, liking their photos and commenting on their stories.
He only approaches you after a story or a post because that is more convenient for him.
He doesn’t have to come up with a topic to talk about after deliberate thought and effort.
He can simply look at a story or post that you have made and use that as his way to communicate or interact.
This is a show of very minimal effort.
When a guy puts this kind of minimal effort into corresponding with a girl, he has no real interest in pursuing her in a romantic sense.
This behavior really has nothing to do with him being shy.
The both of you have known each other for almost ten years.
Though he got engaged and broke off the engagement within the last six months, the time before that was more than enough for him to approach you romantically if he truly had a romantic interest in you.
He also had the added benefit of having a sister that is a good friend of yours in whom he could have used to try to get the message across that he liked you romantically.
He never took advantage of any of this.
With this understanding, it is best to leave it as it is.