Three years back somebody of my group of friends got a girlfriend. Ever since he got together with her, me and the other friends of the same group did not hear from him again, despite our efforts to meet up again or just having a casual chat online. This feels a bit like he turned his back to us.
Yesterday my girlfriend and I got invited to the wedding of he and his now-fiance. We do not feel like going because of these last years, acting like nothing has changed.
There is a website where you can respond to the wedding. I do not want to be cruel in the response (wishing him all the best with his soon-to-be wife), but also not beat around the bush for the reason.
What would be the proper way to decline this invitation?