It starts like this.
Sonic and Sally have a 'dispute'.
That's what the council calls it. A 'dispute'. A 'little tiff', if Alicia Acorn's input is worth anything, and a 'long time coming' if Maximillian's is to be considered similarly. The council, once again, debates the potential dissolution of the Freedom Fighters, and argues over the merits of re-establishing a royal brigade.
Nicole is nowhere to be found, which is for the best, honestly- too much time listening to people argue over whether you can be trusted will turn you into someone that you, personally, wouldn't trust.
Charles - Uncle Chuck, rather - just presses his lips into a thin line when he hears the news. Rosemary Prower successfully leverages the council's constant bickering into a pure stalemate, which is a skill she has become frighteningly good at, and the other Freedom Fighters - Rotor, Antoine, Bunnie, and Tails - try to keep their noses out of it while not-so-secretly asking indirect questions of each other about what they think the couple was actually arguing about.
The arguments didn't really become more or less common over the years, but the subject being argued over became gradually more obtuse. It used to be about Sonic's pigheaded 'you can't stop me anyway, so nyeh' method towards saving the day versus Sally's pragmatic, long-term war plans that were largely responsible for keeping the Freedom Fighters on the map, and as much of the Eggman Empire off of the map as possible.
It would be a lot easier to solve if just one of them were objectively right, but for all intents and purposes - they both were, which means neither of them were.
They'd long settled that point, and so, every argument devolved into the minutiae of minutes (whenever such an argument happened). Whether they should have turned left or right, or whether it would have killed Sonic to wait for a second before breaking into a sprint, or whether Sally could just 'cool it' already with the whole 'stick to the plan' thing.
So: things were tense between them, and nobody could really explain why or over what.
As it so happened, they didn't actually need to worry - after four or so hours of trying-not-to-look-like-they-were searching for Sonic and Sally, Bunnie found the two somewhat stuck together in a tangle of limbs, breathless lips, and exhaustion in Sally's room.
Nicole, who was somewhat stuck between them, was the first to notice the rabbot, and immediately vanished out of existence out of shame and embarrassment. Sonic and Sally, meanwhile, just wished they could disappear, and avoided any and all eye contact while they waited for Bunnie to stop laughing.