English translation for the extended meaning of 備胎

[tooironic]

Obviously 備胎 literally means "spare tyre", but I'm looking for a translation of its extended meaning.

 

For example, when a guy who has been dating a girl for some time says 我其實沒有備胎, my understanding is he's saying that he has no "back-up girl" - i.e. he only has eyes for his current girlfriend, and no one else.

 

I was wondering whether there is an equivalent metaphor in English.

 

Thanks

[TheBigZaboon]

Not very elegant, but how about a "fall-back."

Or in the girlfriend case, "I don't have anybody else on the string."

 

I often find that the first meaning that pops out of my head, or is suggested by someone pushes all others out of my mind for days. 

[mouse]

R&B singer and songwriter The-Dream often uses the phrase "side chick". E.g. from the song Love King: "Half to my main girl, quarter to my side chick".

[imron]

Plan B?

[陳德聰]

When we refer to people as our "back-up" in this context... it is a pretty equivalent metaphor isn't it?

 

You're supposed to keep a back up of your hard drive so that if your current set-up explodes, you can start over with said back-up, right? It's the same sort of catastrophe preventing method as keeping a spare in the trunk of your car.