In this lifestyle, like all others, there is a wide spectrum, some no doubt are into lots of extreme humiliation some not, some like no condom others like us insist on it. It depends on the couple and their " friend(s)". Live and let live. We're pretty normal I'd say, both professionals and actually both doctors, yes even doctors can be kinky! That said we are very careful about our "friends".
For us it's less about humiliation, although obviously there's some if someone else has their penis in your wife's vagina! It's more about just good old fashioned uncomplicated fun.She likes to feel full with a wider cock, she likes being able to let go and she is sexually excited by black men. I like to watch her "lose it", to see her pussy stretched wide, watch someone else talk dirty and graphically tell her what to do and yes the man has to be black, don't know why no doubt there's a deep reason somewhere. Works for us and a win win we both agree.
As I've said in other posts it's made us stronger and we communicate a lot better - something that was becoming a problem due to our heavy workloads. The "events" are just a massive de-stressing activity, although less recently due to us both being very busy for obvious reasons. Outside of the actual "events" and in the immediate lead up to them we're a completely normal couple, we share stuff in the same way, we do the usual stuff, we have sex and are a loving couple etc. Has it has changed our relationship yes it's added an extra dimension, she become more confident in her sexuality ( which has benefits for me!), we've enjoyed finding words to describe it (blacked is our current favorite) and I've enjoyed stepping back and losing control from time to time.
For those couples wanting to try it out don't be put off by the porn and assumption that the man has to be a sissy and the wife a slut, you don't! Just give it a go, be brave and sit back (or lay/bend over if you're the wife) and enjoy the ride ( again literally for those wives out there)