^Its called bullshit is what is. True, both parties know, so technically it's not cheating---behind the other person's back. It's cheating the "system", the moral system.
I personally know several couples that have engaged in swinging, and what led to all of them, was ultimately what is prevalent in this day and age, romantic and personal laziness. Sure they "loved" each other...but that "for better or worse", didn't matter.
Rediscovering why you fell in love with that person, yes things do grow old, as is the natural process, but when I have talked to people who have been married for 50+ yrs, they laugh at the swinging bullshit, because they know it's a pandora's box of problems.
What next, cuckholding..
And I bet that "loving couple" you know...what happens when one of them is hooked up to a dialysis machine and or has to be driven to the hospital, and the other wants to get their freak on? Does sexual gratification come first, or does that other person's health. Therein lies the moral part.
People today are soo quick to jump into the quickest "remedy"/fad, and then get lost in it...
Not taking time...
BTW, a ironic thing, one of those couples I know who were into swinging...it ended when the husband "swung" the wrong way.