*nodnod* Totally! I'm better at mixing and matching in some fandoms than others. And in Baccano!, for example, I think I have a similar case to the one you describe -- I'm pretty cool with either Claire or Firo having a thing with Luck so long as it's set before they meet the girls they will eventually marry (or so long as it includes the girls in a positive light), but breaking up Claire/Chane or Firo/Ennis to put them into other pairings is really tricky for me to get my head around. They're so good together! (...when Claire is first starting to romance Chane, he buys her a dress that has hidden sheaths for her knives. THE BOY PAYS ATTENTION TO HER INTERESTS WHUT.) I could believe he loves other people also, but only in a way that makes her still central.
So having them on my character list this time around was a little tricky, really. ^^;