You’ve always gotten unexplainable bruises and cuts, some worse than the others. Maybe you were clumsy or just prone to injuries more than other people but it’s gotten to the point where you barely notice when it happens. But Caleb always notices whenever you have a new bruise blooming on your shin or a small cut on your arm. And he’s always there to hold an ice pack on them or bandage you up. The first time Caleb presses an ice pack a bit too hard onto a fresh bruise of yours it’s an accident. But your hand that’s clutching his arm squeezes a bit tighter and an almost imperceptible whine comes out of your lips… And suddenly everytime you have a new bruise or cut, Caleb manages to press a bit too hard. Which is strange to you because he’s always so careful and meticulous about you and your safety and wellbeing. However, every time you come to him with a new injury he makes it so that his touch hurts for a split second before he’s back to making everything feel better. You think he must just be getting more and more careless since you’ve been getting injured for so long and so frequently. But he’s really taking the opportunity to have you squeeze him a little tighter and to hear noises from your mouth that he wouldn’t be able to hear otherwise.
On the flip side… Caleb who always overexaggerates everytime you retaliate against him by hitting him/pinching him/etc. He’ll act like your hits hurt way more than they possibly could hurt his stronger and much bigger body. But he’s been doing it for so long you think you’ve become really strong or he’s just more susceptible to pain than you’d think. Either of which are greatly beneficial to you when he does something that you deem worth punishing him for via small slaps against his arm or pinches on his thigh. He knows that the more you think you’re hurting him in these moments, the more satisfied you’ll be and the more likely you’ll be to continue since you got a strong reaction out of him.
You don’t know that obviously you’re not hurting him in any real capacity, at least not as much to warrant the reactions that he’s giving. But he continues to act because he loves your hands on him even if they’re enacting small vengences against his skin. He loves when you pinch his thigh and he jumps more than necessary for the feeling and you giggle and pinch the slightest bit harder, to which he starts to feel the pain and has to bite his lip to refrain from a different type of noise escaping his mouth.