Significant Other is a shift from other apps that share everything with everybody, everywhere.
It's just for you and one other.

Whether it’s a website link you want to discreetly share and not appear later in your browser, a photo you don't want your kids to stumble across, or a message you don’t want a co-worker to accidentally see pop up during staff meeting, Significant Other keeps your messages guarded and exclusively between
you and your partner.