Nikki, I am so glad to read that you called your friend and have reconnected, that is wonderful. I do understand how you feel about your ex and your friend in regards to all of you getting together. One of my really good friends in HS ended up marrying the first guy that I ever had a crush on. I had a crush on him for at least a year, then I finally dated him for a while, thought I was "in love", thought he was "in love" and then abruptly he broke up with me. He ended up breaking up with me (I found out later) to be with my friend. I was hurt and shocked and for many years found it difficult to be around them, especially with DH. That was 19 years ago and it really damaged two friendships, but now, I do see them once every so many years and we are friendly enough, but we still have that uncomfortable feeling going on. I hope you can reestablish a relationship with your friend, there is nothing like childhood friends.
Now to answer your original question, I have two good friends from HS that I have know for 26 years and I treasure them. When I came home from Italy this past summer they arranged a get together with 5 of our friends, some I hadn't seen in 15 years and it was one of the best nights out I have had. It is great to connect with people you knew in school, it is such a different kind of friendship that spans the years. We promised that once I move back to the US this year we will do it more often and I greatly look forward to it.