Important/helper tags-
Ball gag-
surgical mask, mask, gag under mask, ball gag, gag, gagged, mask pull, removing mask, saliva, saliva trail,
Tape gag-
surgical mask, mask, gag under mask, tape gag, gag, gagged, mask pull, removing mask,
Make sure to use negative with tape gag-
lips, mouth
Dildo-
surgical mask, mask, dildo under mask, dildo, fellatio, mask pull, removing mask,
You can also do a POV first person removal of the sub's mask if you like, however it's definitely a lot more inconsistent, be prepared for some larger batches. (Or getting creative with inpaint) tags are-
1boy, pov, pov hands, removing mask,
For a before and after shot/comic type deal with the girl wearing the mask normally then pulling it off to show the dildo- (or gag, but harder, read further below)
multiple views, before and after,
Generally fun or helpful other tags-
heavy breathing, steam, saliva trail, saliva, nose blush,