And sorry, OP, I didn’t intend any of that nastily — I was running out the door and it came out more trenchantly than I intended.
See it as a learning moment. People-pleasing fundamentally doesn’t work.
You can’t exchange services for friendship, and you certainly can’t exchange your services for overtures of friendship to be extended towards your husband by the fiancé of the person you’re performing services for. That’s a pretty complicated set of obligations and services there.
Look at exactly what your expectations were here, and ask yourself why you were doing these things for your friend, and what it is about your husband not being invited to the stag that has made you realise that other people see the set of relations differently. I mean, you say ‘we were there for her’ before she met her fiancé, and that she was your bridesmaid, but she’s not the one having the stag do! You say her other close friends’ partners were all invited, but presumably the groom thinks of them as his friends, not hers. He doesn’t think of your DH that way. That’s not anything your DH or the groom are doing wrong. They’re just not friends.
ETA And if this has upset you, you should think hard about why you are doing things for your friend. Do things for others because you want to, and not unless. Doing them with implicit conditions attached that only you’re aware of isn’t going to work for anyone, including the bride, if you’re clearly upset on her hen do because you think your services should have elicited an invitation to the stag for your DH.