Suppose you’re flirting with a certain special someone, and they start tickling you. You can imagine some situations where that’s fun, right? Flirtatious. Potentially leading to some nookie. Now imagine that you are feeling annoyed with that same special someone and they try to tickle you. It feels irritating, right? Like maybe you’d want to punch that person in the face. It’s the same sensation, but because the context is different, your perception of that sensation is different.