@readingangel5 Well grabbing tail is Rimukoro's euphemism for sex, so it is basically a PG rated censoring of 'Fucking' to 'Fluffing' (the tail). Your example is the equivalent of him pouncing on her and feeling her up or skipping foreplay altogether.
Remember earlier in the series when she turns tail access off for a fer days as punishment, then gives him bedroom eyes under the kotatsu, and one "sex" scene later Homewrecker Sora shows up and almost NTRs Senko. In a recent chapter she even shamefully admits she enjoys the "sex" too, as in pre-modern traditional marriages it was believed the wives didn't enjoy sex, their enjoyment wasn't even considered.