This is set somewhere near the end of "Heroes & Villains." It's the wedding we didn't get to see, but I guess because it had so much stuff going on that's why it's a separate story.(view spoiler)[Basically, it's the wedding of the century and everyone is there, including the entire League of Superheroes, so they leave the Junior League in charge of the headquarters. So of course everything goes wrong and some kind of alien blob thing escapes and they're all going to die.
There's a kind of hot sex scene between two of the Junior League guys. Plus I wanted more of the wedding because I like that kind of thing :) (hide spoiler)]