Reaction?

I went out Saturday night.  My friend and I went to dinner and then to see a production of White Christmas, one of my most favorite holiday plays/movies.  My previous trainer and friend had very randomly text me to invite me.  We had been out of contact for a few years, when this random text showed up last week.  I was excited to go see him.

As we text about the play he included sentiments like "I'm so excited to see you" and "I can't wait to catch up".  He asked me to hang around after the show to see him.  While waiting for the show to start, I perused the program and saw his picture and biography, which ended with "Thanks to my wife."  There were a few other people listed after that, but wife stopped me.  He's married.

He wasn't married when I knew him two years ago.  He had been dating a girl, but he kept telling me they weren't serious.  Now, I do need to mention that he's 7-8 years younger than me, and although I find him highly attractive, while we were acquainted he never did anything to make me think he thought the same of me.  We went out occasionally after the gym, but it was a strictly platonic relationship. 

I enjoyed the show immensely.  It was well done for community theater with unpaid actors and actresses.  I was glad I went.  It was triggering for me, but not as bad as I had anticipated. It was extremely helpful to have my friend with me.  She was great.  I didn't wait around afterwards to see him.  I couldn't do it.  He's married. 

Another friend, who knew about the plans for Saturday, called yesterday to catch up.  I told her all about the evening.  When I finished, she had quite the reaction.  "He's married?  Wow.  Don't you think it's kind of inappropriate that he text and invited you?"  I did think it was a little unusual, yes.  "Do you worry you're walking around with some type of hidden sign telling married men you're available?"  Ouch.  Am I?  She was very upset for me.  Co-dependent?  Yeah, a little.  But is there some truth to this?  I don't know. 

So today, I'm confused.  After two years, he text me and invited me to come see him perform.  Is that innocent or not?  We share a love of music and theatre.  We had talked about it before.  Is what he did inappropriate?  Why can't I answer this question? What type of reaction should I be having to this?  I don't even know. Or should I be having a reaction? 

Until now, I would have thought this was all my issue.  Even when men obviously flirt with me, I assume I'm misinterpreting.  I feel like I have no gauge for this kind of thing.  None.

He text me afterwards to say he was sorry I didn't wait after the show for him. I couldn't respond. He's married.