This is ridiculously vanilla, but I really like when one character is holding the other while they they masturbate, just teasing them with light touches and dirty talk, eventually taking care of their own needs once their lover is really getting into themselves.

Bonus surprise mutual masturbation is also great, or a helping hand getting repaid with oral is always nice.

Consensual humiliation in a public place.

Um, yeah. I just like hands and mouths a lot.