Dialogue Jin: I’ve been using those (chopsticks). Kame: It’s okay. Taguchi: Uwaaa~ an indirect kiss! (Kame reacts, appears to be saying something to Taguchi) Jin: Maybe my drool is even in the core of the chopsticks. (?): You’re dirty. (?): Now he’s all silent. Kame and Maki: Delicious!
In this Cartoon KAT-TUN episode where they take part in a “cooking showdown,” Jin reacted to the fact that Kame was going to use the same chopsticks as he did. This means that he is concerned about this because he felt the need to mention it, but to what level , we cannot tell because he’s not on cam. He’s concerned, but we don’t know how or why.
Jin’s comment about the drool can be read as a joke, but it can also be interpreted as Jin trying to say that he really is concerned (or possibly disgusted?) that they are using the same chopsticks. We can’t tell, because we cannot see Jin’s facial expression. But if Jin were really not okay with it, he could have reacted in a more violent manner, perhaps even saying outright that using the same utensils is disgusting or directly advising Kame to use another set. However, he simply allowed Kame to go on using the chopsticks.