<human>: Could you distill the essence of the text into 1-3 sentences?

My ex and I were together for half a decade. We traveled for 2 weeks to Greece last December and broke up shortly after. In Greece, we made about 5 or 6 friends who I still keep in touch with on Whatsapp and through social media. I talk to 3 of them about once a month and we are very close friends. We have a group on whatsapp where we sometimes share updates but I don't post in that anymore because my ex is in it and we are not on speaking terms. 

Today I get a message in the group text from my ex saying "I will be in Greece soon. I bought the ticket on a whim. Hope you guys can meet up" this is making me feel extremely annoyed for a few reasons. First, I'm jealous that he gets to see our friends and I don't. Second, I'm worried that the friends are going to start liking him more than me after the trip which I know is very immature but I can't help how I feel. Third, I feel like my ex purposely wrote in the group message so that I would know that he is going. We are not connected on any social media sites anymore and that is the only way I could find out. He could've texted our friends on whatsapp individually if he wanted to avoid me. I just want to feel indifferent towards this and it's really bothering me that I care so much Any advice?
<bot>: my ex is going on a trip to a country where we have a lot of mutual friends and it's really bothering me