I like to dress up like in my avatar, wear chastity, and serve them in any way they ask, like
Licking her feet and sucking her toes while she's getting fucked.
Her sit on my face while she sucks on the bull
Her 69'ing me on bottom, watching his cock fuck her. Even better if she's mildly humiliating me or telling me how great it feels
Her taking opportunities to play with my caged cock throughout the encounter, teasing, humiliating, whatever. It's the tease and denial of it all that has me hooked.
Fluffing, fuck-licking, cleaning her cum off his shaft, etc.
Licking up the cum
Letting the bull fuck me or use me, within reason of course, not into hard extremes.