Oikawa: Oikawa would raise his eyebrows in irritation, not believing that someone influenced his partner so greatly that they would actually consider doing it. He would ask them about who exactly they talked to, thinking about accidentally running into that particular human being and very discreetly telling them that if they ever tried to do.
Oikawa would know about his partner’s insecurity and self-consciousness in regards to their looks and realizing that this issue affected them enough to consider plastic surgery, Oikawa would definitely begin talking honestly and seriously to his partner. His voice might even sound a little stern, while he was trying to make clear that there was absolutely nothing that wasn’t wonderful about them.
Kuroo: Kuroo would get an upset and almost disgusted look on his face once his partner would tell him about the idea to get plastic surgery performed on them and how they even got that thought. He would be slightly disappointed that his partner would have believed the person who advertised it but at the same time, having known of their insecurity for a long time already, he would be able to understand why they felt that way. He would definitely be against it, trying to make clear that a plastic surgery wouldn’t cure their problem. Kuroo would want his partner to gather strength and confidence from within, instead of paying money to make minor changes. He would also listen closely to the description his partner would give him on the person who advertised it, planning to find them and set things straight.
Ushijima: Ushijima would clearly tell his partner about the manipulation they would have fallen for once they would bring up the story of that incident, perhaps even stating straight facts that if one used a red marker on every person, basically everyone would have to undergo plastic surgery. He would stroke his partner’s cheek and despite the strictness in his voice, they would also be able to hear the warmth and the care that he was feeling for them. Ushijima would make clear that his partner definitely did not need plastic surgery and perhaps suggest that next time they went to the mall (or wherever they met that person) he would join his partner, to see who on earth dared to plant such a worthless idea in his partner’s head.
Bokuto: Once his partner would have told him about their experience with the person who advertised plastic surgery, Bokuto wouldn’t take it too seriously, assuming that his partner took the suggestion more as a joke than seriously. It would take him some time to realize that his significant other actually took it to heart and were honestly thinking about getting plastic surgery done on them. Once he would get to that point, Bokuto would exclaim loudly that he didn’t understand why they took it so seriously, as to him there were basically no imperfections in regards to his partner’s physique and personality. He would take his partner’s face in his both hands and tell them in a calmer voice that people who didn’t like them for who they were didn’t even deserve their energy and time.
Aone: Aone would stare at his partner with a shocked expression, feeling irritated about the person who made his partner feel this way. He would make sure to clearly tell them that there was absolutely nothing wrong with them, blushing slightly as he would do so, claiming that plastic surgery wasn’t the way to go about it. He would be slightly speechless, wondering about the right words he should choose in order for his partner to understand that they were perfectly fine the way they were. He might go for pointing out all the qualities (which would basically be everything about his partner) he liked about them and would definitely miss if they decided to change those.