Has swinging ruined my marriage ?
Totally.
We used to have the most fantastic relationship, amazing sex life, she was my best friend. She suggested we try this out, she wanted to try things and I wasn't averse to the idea. We were members on here a while back, had some fun, but I found out my wife had her own agenda and could not be trusted.
I think if it works for you it's great, and I admire those couples who can trust each other so that this works for them, but for us, well if I could find a way out of our marriage that wouldn't affect our kids then I'd be gone tomorrow.