What I find delicious about the situation with the chopsticks is that the little details are what make it embarrassing for the leads. On the face of it, monogrammed chopsticks are a little ostentatious but not a big deal.They're Reimu's, to be used by her and guests at the shrine that shares her last name, so having that name on them isn't unreasonable. But with the added context of 'and also Marisa is pretty much always there and the two of them will be eating together regularly with utensils marked with Reimu's last name' it feels like something trying to turn their subtext into text, and so they react to it.
Bonus points if Reimu ends up reserving that second pair for Marisa's exclusive use rather than allowing other guests to use them.