Imagine Person A and Person B of your OTP dating; except A gets really jealous everytime person B does even the slightest thing w/ another person, or goes out with friends at night without them. Like, A is all for attention and they hate it when B doesn't focus on them a lot.
One day B comes home and A's sitting on the couch, all grouchy because B was gone for so long, probably out with friends.
B knows why A is so upset and apologises by smothering them with a bunch of kisses and cuddling up with them on the couch watching A's favourite movie~.