After watching the movie I realized something. Spinel seemed a lot like Pink Pearl in many ways. So we know that Pink Pearl was taken away most likely because she became friends with Pink Diamond. And we also know that Pearl may or may not have been in a relationship with Rose/Pink. So I realized, what if Pink pearl and pink diamond developed a romantic relationship? And what if Pearl wanted to be with Pink because she likes her for who she is but Pink Diamond only was with her as a way to get over Pink Pearl and just because she reminded her of Pink Pearl but little did Pearl know that their relationship was one sided because Pjnk Diamond wanted her to be Pink Pearl and our Pearl couldn’t live up to her. And what if Spinel was created as an apology for ruining Pink Pearl but she reminded Pink too much of her pearl that she abounded her because she didn’t want to be constantly reminded of Pink Pearl. And then she later felt guilty and found Amethyst and she reminded her so much of Spinel and Pink Pearl that she took in Amethyst and thought of it a closure to what she did to Spinel and reminded her of Pink Pearl?
i think they will form some sort of relationship (not necessarily romantic), as the diamonds might ignore spinel like they did to pink diamond, and pink pearl will be her only comfort as a result. this could be a conflict presented in season 6, and perhaps pink pearl will become spinel's new best friend.
Its just i noticed how similar Pink Pearl and Spinel are so it made me think that SPinel and Pearl are replacements for two different aspects of Pink Pearl and Pink Diamond left Pearl because she thought it would just be a replacement for her relationship with Pink Pearl and wanted to be in a relationship where she liked someone for who they were and not as a replacement. And then i think she really liked Amethyst as a person because she reminded her of Spinel and then something else that no one else notices is that its implied that Anethyst had feelings for Rose and was jelaous of Greg, beause most fans interpret it the opposite way. And the reason why Amethyst and Pearl have such a strained relationship at first is because they both had feeling for Pink Diamond.