The unspoken metaphysical axiom of romantic storytelling is that there is precisely one person out there that you are meant to be with, and you either find them or you don't. If you find them, great! If you don't, at least you can say you waited for them and thus never betrayed them. The worst thing to do is give up the wait and settle for someone else, the act of betrayal which can never be taken back.
(This is in line with Gnosticism, which believes that monads got split into two pieces by Yahweh prior to being imprisoned in the material world, each of these half-monads being what we call souls. Each soul started out trying to find its original complementary half in order to recombine into a full monad which can then transcend the material world (provided they do not reproduce). Duets are the musical representation of this:
https://trueleft.createaforum.com/counterculture-era/is-counterculture-still-alive/msg18929/#msg18929https://trueleft.createaforum.com/counterculture-era/recommended-music-to-listen-to/msg21840/#msg21840 (and subsequent Duet Month posts))
Almost no one these days believes in this anymore, unfortunately.....