Complicated Situations - Taken people

What if you met the love of your life but they're already married?

That's an extreme, but what if you met someone and you knew within a week that they suit you and you should be together.. Do you fight for it, or do you sit on the sidelines? Guess that's down to what person you are, and weather you believe in fate or making everything happen yourself.
If you believe the 'if its supposed to happen, it'll happen' you'd sit on the sidelines, patiently being their friend waiting for it to happen...
But if you re the opposite and think that people make their own fate you'd slowly push your way in..

But neither of those are an answer.. You can't force someone to be with you-even if you are meant to be, especially if they re taken, because you don't wanna be the reason they split up and you definitely don't want to be a rebound.

That's alot of issues for liking someone, so is it easier/for the best if we just ignore our feeling and just be friends, or is that even worse?