Remember the days of Bill Clinton when we were expected to believe that Bill's definition of 'sex' didn't include the oral type his intern performed upon him? Do you also remember the pundits on TV bickering over the definition of sex after that fiasco?
Though I personally believe most any description of an act with the word Sex in it (such as Oral Sex), is indeed a sexual act and the pundit discussions were ridiculous, I have to respect them to a point. What they were really discussing was how the definitions of words can mean different things to different people, regardless of what Webster's or Wikipedia might say.
As poly people having discussions and defining relationships I think that point is even more pertinent.
For example; "Hey honey, I'm going to the Play Room to fool around with Lucy for a while."
Does that mean they are going to kiss and snuzzle a bit?
Does it mean they are going to feel each other up but not have sex?
Or does it mean they are going to have full-blown porno sex for the next hour?
At this point we don't really know what it means, do we?
Or how about this one. . .A couple talking before a party about engaging with other people at the party agree to give each other a 'sign' before engaging with anyone else.
Sounds like a great agreement right?
Maybe. Except one person thought 'sign' meant 'Talk to me first!' and the other person thought it meant 'Just get my attention so I don't wonder where you went'.
Now you can see where we have a situation as follows: Fred and Ethel go to the party together with their 'Give me a sign' agreement. Fred and Lucy start flirting. Fred catches Ethel's eye from across the room, gives a nod in Lucy's direction along with a wink, and merrily heads off to the Play Room with Lucy to. . . . . . ????
To what? We don't have a clue do we? Well, neither does Ethel really. And at the same time Fred thinks he has been a good poly boy and followed the rules wonderfully.
We all know what happens next right? On the way home from the party Ethel explodes at Fred asking why he didn't talk to her. Fred, confused, says he did give her a 'sign' before he went off and shagged Lucy. At which point Ethel explodes again saying "I thought you were just going to fool around, not have sex!!" Fred, scared for his life now as he should be, doesn't have a clue what just happened.
And honestly, neither does Ethel. They will probably argue for hours and possibly never figure out what went wrong.
Assumptions. That's what went wrong.
They each assumed a common word, term, or concept that they were discussing was explicitly understood by the other person. In actuality, they had somewhat differing understandings.
I actually learned this from an experience much like the example above. During the resulting discussion my partner made a passing remark about one of the terms we had used in defining our rules that didn't fit my understanding of the term at all. Hardly two or three sentences later and we both knew exactly what had happened. From then on I have tried to always ask for definitions of words upon which understandings are based. And to this day I am amazed at how many misunderstandings are avoided so simply.
Don't believe me? The next time you hear someone casually mention 'Sex', ask them to define what they mean by the word 'Sex'. I bet you will be surprised by at least one thing they say. And if you are in a group, ask the group if they all agree with the definition that first person gives. I virtually guarantee you will be surprised by their responses.
Having conversations about boundaries, rules, expectations, needs, etc. is all very well and good. But if you and the person you are having the conversation with are speaking different languages it will all be meaningless in the end.