Ideas for songs to use in a short film?

I am making a short film about two lovers separated. They come together again in the end.

This is just for fun, so I want it to be super over-the-top. What’s a really corny sad breakup song to have in the background? Instrumental is preferred, but I’m open to anything.

Also, at the end I want to have a happy reunion song. Ideas for that?

Alternatively, ideas of scenes in videos that exemplify this style would be much appreciated.