The thing about the mirroring and uncanny synchronisation these two display is that they are the only ones within the band who constantly do it.
It’s literally proven by psychologists through behavioural studies that if a couple spend enough time with each other they will eventually start unconsciously mirroring each other’s actions and become generally more in sync.
"You can’t mirror someone if you’re self-absorbed. You must pay attention to the other person and observe them carefully"
"If you mirror someone effectively, they can’t help feeling "in sync" with you, and they will instinctively trust you — the first, giant step toward love"
"While mirroring and getting "in sync" with someone may start off as calculated and can even be intended as manipulation, being "in sync" can’t be faked for long; it soon becomes true"
And who are we to argue with science?