BUR #31080 has been rejected.
mass update favgroup:35539 -> male_spanking_female
mass update favgroup:35542 -> male_spanking_male
mass update favgroup:35541 -> female_spanking_male
mass update favgroup:35540 -> female_spanking_female
Now, this is going to be a long one, so bear with me here.
Just because tags like mmf_threesome have the letters M and F in them doesn't mean they work well as precedents to the proposed tags. In fact, I would argue they're actually a good reason not to use the suggested names. The various threesome subtags make no implication over who is taking the initiative, just that there's at least two x and one y gendered character in the post. Because they've been around for years already, people are going to look at a tag called m/f_spanking and assume it's for "spanking between one boy and one girl", regardless of who's actually dishing them out. The tags, if they are to be created, should be male_spanking_female, male_spanking_male, female_spanking_male and female_spanking_female.
As for whether they should be created, however, I don't know. We need to consider that it opens up the floodgates for users to create up to four (or maybe even more) different gendered tags for all sorts of other stuff, which is something I can see some arguments both for and against (even though I'm leaning toward "yes" after writing this post). Do we really want male_fingering_female, female_pegging_female, female_licking_male_nipple, male_grabbing_male_ass and so on? A lot of those concepts are already very easy to search for, to the point where a tag for them would be nothing but superfluous. male_grabbing_male_ass, for example, is literally just a grabbing_another's_ass yaoi search. female_grabbing_female_ass? You guessed it, grabbing_another's_ass yuri.
On the other, ass-free hand, however, the more you think about it the more you realise that some of these are actually a pain in the afore-mentioned ass to find without tags for them. Consider the following: guys who like girls' fingers up their ass and guys who like to stick their fingers up girls' asses are both delegated to the same searches, despite these two fetishes being very different (1boy 1girl anal_fingering, hetero anal_fingering for blue users, and so on). From the quick scrolling I did, there's about one "male being fingered" post for every two "female being fingered" posts, meaning both parties are subjected to many unfilterable false positives. Tags like male_fingering_female and female_fingering_male are essentially necessary to make both these groups of users happy.
As for another example, if you want posts where a girl is grabbing a guy's ass, you're even more shit out of luck - grabbing_another's_ass is 99% the other way around. If you're an alcoholic, then try taking a shot every time you find man ass being grabbed in the grabbing_another's_ass hetero search. You'll be out of rehab in a week. Also, if you thought about being clever and doing a grabbing_another's_ass femdom search, then think again, bucko. femdom can be tagged on yuri posts, meaning you'd actually need grabbing_another's_ass femdom hetero, but even that search is a mixed bag, containing stuff like post #1568051 and post #1469778. Overall, I feel like this example is actually worse, because female_grabbing_male_ass is all but unsearchable without a tag for it.
When I mentioned this BUR opening the floodgates, what I was referring to is that even if we agree that we only need male_fingering_female and female_fingering_male, and that we don't need male_fingering_male or female_fingering_female, you have to remember that a decent chunk of our users don't like to think too hard about things. They're just going to see the two approved tags while browsing and assume that they should also be using the other two, even though we deemed them unnecessary. We'd have to approach each fetish on a case-by-case basis, determining which of those tags we do or don't need (if any) and then deprecating the superfluous ones (if any) in advance. Now, I personally don't mind this approach, but it absolutely needs to be put to a vote.
tl;dr: Consider this second BUR a vote not just on these individual spanking tags, but on whether we want to give the green light to making such tags for any other fetishes where some or all cases are unsearchable without them.