Most Helpful Guy
That's a tough one... One of the closest people to me is an ex-gf where things just didn't work out - we were just id different places in life. But that ended on a good note. It's one of those strange anomalies. Nobody knows you as well as an intimate partner, especially when you've both shown each other everything about yourselves. They can be a very valuable part of your lifetime support structure. That is in the norm at all though. In fact, it's probably very, very rare. If you feel like you would have a relationship like that with him, then by all means. That doesn't sound likely though, so you probably shouldn't. Plus, you never know, it could cause some drama or something with him and/or his new GF.
If you absolutely have to quell your conscious so you can move on, then maybe try to convey what you want to say in another more discreet way?