for those who want an easy copy paste :

futa_taker_pov, taker_pov, futanari, cum, from below, hands on head, motion blur, motion lines, thrust, thrusting

Tip: "Hands on head" is an incredibly vague trigger prompt for what its intention is. Understandably, you're far more likely to get your character clutching their own head instead of the viewers.

After an annoying amount of trial and error I got the desired results by using "Holding viewers head" and "foreshortening" instead and adding "hands on head" and "holding own head" in the negative prompt. Make sure you're using "solo" as well so you don't unintentionally get any other characters (or the viewer) grabbing the futas head either.

Might want to change the trigger prompt to make it easier to include multiple characters (like spectators), or have the receivers hands doing something (like holding the futas thighs) without getting janky or disappointing results.