Well that's true, but as far as i remember they didn't know that solus was human before she remembered her old life. They are more like partners. So he encountered phloria before they knew i think, as for kamila i don't remember.
She doesn't even have a body, we don't know if she's gonna gain one after the purple core. There is many problem, moreover the author explained that they depend on each other and that her "love" toward him was just bc she can't even live when he's not here bc of her condition when there is no geyser closely.
They also merged they memory and all... this was not really a "healthy" relationship before they try to put limit. Well there is many reason for their complicated relationship, and sorry for my bad english, hope it's ok...
