<human>: Can you succinctly summarize the text in 1-3 sentences?

We dated during our freshman year of college for eight months and have been broken up for like 18. There was very little contact during that time, but recently we had a 5 minute conversation on the sidewalk that didn't seem that tense.

I feel a little guilty because things fell apart based on me losing interest, not from any specific event. This has caused me to try to stay out of his way.

Now, I've made a friend (who is the wrong gender to be a romantic issue) who is part of the subject-club that my ex is in charge of. She has invited me to several of the club's events this next school year. Am I obligated to send a message warning my ex that I will be there? Do I need to give him veto power on my attendance?
<bot>: I haven't seen my ex in a year and a half but might go to social/academic events where he is involved. Do I need to give him a heads up or vote about my presence?