dumping a lover for an ex, and back again

[ladyhatshepsut.livejournal.com]

With the six Avengers and all the people around them that be counted as part of the team or support, somebody might have used this plot line for this fandom.  I read this originally in an X-Files story.  I do remember that it had the central four characters: Mulder, Scully, Skinner, and Krycek, but it's been several years since I read it so I don't remember who dumped who to be with who, so I'll just refer to any four as A, B, C, and D.

A and B are dating/sleeping together/living together, whichever.  A is totally in love with B.  C, who has been away/missing/out of the picture, suddenly shows back up.  B and C used to be together and B is still in love with C.  B throws A over to get back with C.  A is broken hearted but leaves quietly, knowing he was second choice anyway.  After a short, but intense time, D pops back in the picture. C is in love with D, only getting with B because D wasn't around.  C leaves B for D, same as B did to A.  After a length of time, D decides he cannot deal with C's intensity/crazyness/neediness/whatever and ends the relationship.  Brokenhearted, C goes back to B, who is ready to dump A again.  (Actually, I think somewhere along the line the dumped one get fed up with the whole thing and tells the returning ex to shove it.)  Get the picture?  I hope this isn't as confusing to you as it's becoming to me.  It's basically a vicious game of musical lovers, with uncaring lovers and broken hearts all around.

Goddess, I really don't want to tag every possible pairing that can come out of this...