We see in Hit the Diamond that Ruby and Sapphire can barely function without each other. We all were like ‘oh, its no big deal! they’re in love!” and I thought that too! But now, with Alone at Sea, we see that not only is it for love, but power. Lapis hates Jasper. They hate each other. But lapis says ‘We were fused for so long…” Think all the way back to Strong in the Real Way. Garnet and Amethyst started to literally lose themselves in Sugilite. SO… Fusion is addictive. The longer you stay fused, the more the counterparts need each other.