I was in a polyamorous relationship with a married woman once, but there was no element of 'sharing' involved. It was just people who were able and comfortable with having relationships with multiple people.
I know I suggested it in the first place, but the 'introduceyourself' tag is generally for your first post, so that we can welcome new users to the community. It shouldn't be used for every post :-)
Thanks @demotruk, I have updated the tags ! It was the autofill that did it :)
And we can indeed have relationships with other married women or men, but to me it should always be openly and honestly, with the consent of all partners involved, mostly for karmic purposes :)