Fauxlationship
A relationship that isn't a "real" relationship (i.e. "We're going out. You are my --- and I am your ---"), but attempts to carry on as one, albeit half-heartedly, despite this fact.

Note: this is not the same as people who define their relationship as an "open relationship", as fauxlationships lack sturdy titles of any sort.

This is similar to FWB, except that the "couple" pretends to be more exclusive than they actually are. They may go on "fauxdates" with each other (like a romantic outing to McDonalds). They don't want to commit actual time and money to go on real DATE dates, but they want to occasionally pretend to do so (usually for the sake of one partner's feelings). They might entertain the idea of being in a real relationship with one another, but the idea never comes to fruition.

Fauxlationships almost always carry on for much longer than they need to, and frequently lead to messy "faux-breakups" (wherein it feels like a break up, but they shouldn't be so upset, because they were never actually dating in the first place).
She and I have a lot in common. We go to the same school, we like the same band, we have a class together. We hang out at each other's houses, and we occasionally have sex. I want to date her, but she doesn't LIKE like me, and doesn't want to get tied down. We'll rent movies sometimes, but she doesn't want to go out in public with me in case anybody thinks we're actually going out. I would complain about our fauxlationship, but at least it's sort of like having quality time with her.