Is this wrong?

So, I was in a relationship with this guy on and off from age 12- 21, we were also best friends for years but everything ended when we called it quits. Fast forward to now. I'm happily married now and me and the guy message each other on fb every once in awhile. He's bisexual and is with a guy. I really miss our friendship. We clashed when we were together but we made the best of friends, I could literally trust him with my life. I really want to be friends again, but don't know how to ask. My husband knows that we messaged each other because I told him. Do you think it's wrong to want that friendship back?