Yeah, great thread topic.
I guess my ex-fiancee might fit into this category. And according to her family, I fit into this category for her as well. Her aunt was an extremely nice person and I stayed in touch with the family (though not her) for several years after we broke up. The aunt's description of our stormy relationship was that we both screwed each other up to the point that we were not fit for relationships with other people after our breakup. And I guess she was right. My ex has been engaged at least twice, but has gotten cold feet on both occasions. And I've just flat refused to consider getting married - even too much talking about it and I'll break up with the girl. My current girl is a sweetheart. And we've been together for longer than any relationship I've had since the ex. But I'm not marrying her either, and as long as she's OK with that, we'll be OK together.
Oh, my, my. Oh, hell, yes.
Honey, put on that party dress.
Buy me a drink, sing me a song.
Take me as I come 'cause I can't stay long.