Book hopping characters

One of my favorite little things about romance novels are interconnected books and characters that make appearances in multiple stories. It's like visiting old friend's every time I encounter them. I got to thinking about this after writing a scene in which each and every one of my heroes made an appearance (They’re all hanging out at White’s. Surprise.) It's the first time they're all together, but not the first time they show up in each other's books. Here's a list of some my book hopping characters: