Pearl: "I don't understand your human relationships."

Gems don't "date" in the way most of our society defines it. I highly doubt Rose or Pearl saw their relationship in the odd and possessive way most of us do.

Example: Ruby and Sapphire aren't "dating"; they love each other more than any other and so are always together.

Pearl loved Rose and Rose loved Pearl, but it's clear it's much more complex than that. Pearls are servants on Homeworld and Pearl is far from a perfect pearl. From what we've learned so far, I would conclude Rose was gifted a pearl for whatever reason and we know Rose is a gentle and loving soul. I'm sure our Pearl was likely to be shattered for her oval shape, her imperfection; Rose would not allow such a thing

Pearl: "Rose made me feel like I was everything."

and of course you would feel that way about the gem who is to thank for you being alive in the first place.

Pearl's love is true, but it's more a worship than a partnership. (Not like we see with Steven and Connie in "Sworn to the Sword". The point of the episode was to make that clear distinction, I think.)

Which leads me to Rose and Greg. Rose is a gem, a hologram, one who doesn't understand human love. We tend to forget this, I think because of Garnet. However, it is made clear they are the exception.

Rose learns true love from Greg. Rose learns true empathy. Greg is her balance, her other half, her partner. Something I don't think Pearl can understand yet.

TL;DR don't attempt to understand the gems relationships with your human terminology for relationships because it doesn't work like that for them. (and it shouldn't for you either.) <3 :-) Love is love is love~