you need mutual consent to be closer with one another while bonding over a shared sentiment.
Barb and Steven were dancing for the sake of dancing, not trying to get closer to one another emotionally like Steven and Connie, or when Steven hugged Amy.
What I still haven't seen is a satisfying answer to how the fuck Ruby and Sapphire fused. Over what notion did they fuse on? Their shared desire to keep Sapphire alive? Was Sapphire having second thoughts about accepting her fate, which coincided with Ruby's desire?