I'm just the editor but here you go:
https://dictionary.cambridge.org/dictionary/english/simp
I challenge you to find a better alternative for 推し活 that isn't verbose.
Just a reminder that in Chapter 1 Ruka says that despite calling them 'Sefure' they haven't actually done it "for real" and that it was just the easiest way to explain it. Whether you believe if she was telling the truth is up to you, but with how easily she folds whenever Suuna makes a move on...
Because giving an adult childish and embarrassing underwear is funnier than being naked.
I know that this is a joke but looking at other Ultra Jump series like Inertia 67%, Mucha could've easily added nudity if they wanted to. Even Jojolion (same magazine) has had some uncensored (upper) nudity.
Please get whoever typeset previous chapters back, or at least have someone who knows the basic fundamentals of proper typesetting go over the chapter because this is a significant downgrade compared to what it used to be.
Nekotofu has not done any 18+ stuff before (that I could find at least). Perhaps he has but it wasn't released under the Nekotofu name. There's some SFW doujins though of various series.