How direct were you with your dh on the night in question Mosschops. Did you say in a fairly controlled, mild tone "I really would prefer it if you didn't go"
Or were you plain speaking, assertive and direct - e.g. "If you go I will be terribly hurt and let down and don't think I can ever forgive you. I will feel like you are not standing by me / defending me on what is an important issue for me"
If the former then I think you should cut dh some slack (as it may be he didn't think it through properly). If the latter and he still went you have been badly let down by dh and are justifiably feeling betrayed.
Could it be that dh just didn't compute just how upset you are by this whole thing? Don't forget that men are not as highly evolved as women , and often have the hides of rhino....