"Who" is a pronoun for living subjects. If you can replace the word with “he,” “she,” or the gender-neutral “they,” use who. “Whom” is a living thing ("object") having something done to them or receiving something, like a blowjob. If you can replace it with “him,” “her,” or “them,” use whom. It can help to temporarily change the word order to see/hear it more clearly.

• Who unlocked my sub’s cage? (He did.)

• I made a flogger for my Domme, who (she) likes to beat my ass before breakfast.

• For whom will I be bent over? (Them.) Change the word order temporarily to hear that it works better as "I will be bent over for [him/her/them/whom]."

• Whom did we invite to eat your pussy? (Her.) Change the word order temporarily to hear that it works better as "Did we invite [him/her/them/whom] to eat your pussy?

"Whose" is used to assign ownership to someone.

• Whose condom is stuck in my ass?

• Bobby, whose balls are hanging in my face, is a really nice guy.

• Whose idea was it to serve hot Cheetos at an orgy?

“Who’s” - a contraction for "who is" or “who has” or “who was” - is used to identify someone who's doing something (or was doing something or has something).

• Nadia, who’s (who is) going to blow the whole team, wears knee pads for comfort.

• Elizabeth, who’s (who has) just cum on my face, was a virgin until yesterday.

• I bought an extra toothbrush for Brian, who’s (who was) planning to stay the night but left after he came inside me. That bastard.