I’ve noticed that twin emotions often have this weird ‘double exposure’ feeling (like when you take two photos on the same frame) or emotional deja vu.
What really helped me confirm these weren’t just my own random feelings was how they’d often come with specific memories or thoughts about my twin that I hadn’t been actively thinking about (especially stuff I thought I’d already processed). The randomness is actually a pretty reliable sign our own emotions usually have some kind of trigger or build-up, while twin emotions tend to drop in like unexpected visitors (usually at the most inconvenient times).