It's surreal to be a "recently separated guy" attending a family-member's wedding.
Partly you're cynical about the whole affair, especially if (as it was for me) the whole "separation" occurs not too long before the wedding in question. Partly it's the in-jokes you can make.
For example, at my cousin's wedding this past weekend, there was this little book, next to the guest-book. It was a spiral bound book of blank 3x5 cards with a title "Suggestions For Marital Bliss" or something like that, and the guests would each jot something quick in there that they thought would help out the newlywed couple. I stood there staring at it wondering what to put in it. One of my family members commented that if I touched that book, she'd break my hand. I asked "what if all I put in it is 'Don't listen to a damn thing Derek says'?" She thought that might be acceptable, but only that.
Meanwhile, my grandmother, also in attendance, seems to be being kept out of the loop on the impending divorce. The general consensus seems to be that several years ago, when my great-aunt was living with her, my grandmother refused to tell my great-aunt that my aunt was dating and engaged to a divorced man. My great-aunt didn't know for like a freakin year or something that my (now) uncle was divorced. Apparently, the family is keeping it from her as some sort of very delayed punitive action. I promised various members that I wouldn't go out of my way to spoil their weird little game, but that I wouldn't lie either. (I don't care that my grandmother treated my great-aunt like shit, my great-aunt treated ME like shit when she lived under OUR roof, so there's little pity here on that front)
But, said uncle did clap me on the shoulder and welcome me into the Divorced Men Club. I told him I was only a Probate Member at the moment, but soon... very very soon...
That, and I'm annoyed that my cousin doesn't seem to have any single girlfriends she could invite to her wedding. What good is a wedding if you can't scope out the bridesmaids?

I'm finding that there are fewer and fewer unattached bridesmaids at weddings anymore. Grr. :-(