I've seen a few couples
My fave was a pregnant couple who were both virgins when they met each other. Neither had ever been with another person OR ever played with toys!
I helped them explore a few fantasies.
HE was very shy and SHE loved watching him with me, but the pressure wasn't exactly helping him perform. Which I found endearing. <3
He loved his wife so much he had trouble fucking anyone else.
(i know i'm hot, that ain't the issue!)
---
I've also seen swingers, together and separate. Once with the wife, once with the hubby, and a few times together.