I'll agree the names are somewhat ambiguous but that's what people voted for. I don't think we have any tongue-in-cheek tags (that's defeat the whole purpose of them imo), so almost_family_friendly also works in our context. Side note: perhaps this is not so on danbooru, but to your point tags are very much like variable names, and should represent the context and what problem it's trying to solve. Having cheeky tags seem to be self-defeating both in purpose as well as in usage, especially for new users who may be unfamiliar on the inside joke.
Anyways in our case, the tag is to identify pictures that are almost family friend, with the exception of one or 2 minor things ruining the image, without any sort of punny-intentions.