For me it's the whole package, I love taking her shopping for sexy underwear, paying for her nails to be done , knowing it's for her bull's pleasure and not mine.
Watching her get dressed up for her bull even gets my little cock hard.
If I'm lucky enough to get to watch them both together, then it's the humiliation of knowing that I could never fuck her like that and knowing that she's had the best sex of her life with another man.
If I stay home when she goes to see her bull, my little cock will be dropping pre cum all night with the intense thoughts going through my head of what they are doing and how hard he is fucking her and where he is fucking her and what position he's fucking her.
Then when she comes home and I see her cum stained pants and she tells me in great detail about what they had been doing that evening (sometimes whilst sat on my face).
Also love it when we are out and about just shopping etc... and she spots a random black guy and gives him the eye and then proceeds to tell me how much she would love to fuck him.
Finally I love the humiliation side of the lifestyle, my wife telling me how small I am, how white guys don't do it for her anymore and how addicted to black cock she is now, and it's all my fault for getting her into this lifestyle and most of all the time she told her mum that she was fucking a black guy and that I know about it.