AlexisC--Welcome to the board. As a single female myself, I can empathize with your situation even though I have not had a similar experience. My advice to you is continue lurking and soak up information from this board (There is certainly a wealth of it here, especially if you have the patience to put up with narrow minded couples who create their own private reality of what swinging is and is not.)
By the dictionary definition I am a swinger, by your personal (and possibly community) definition I am not. Likewise cheating is going to be defined differently by person, couple, and community.
You said a mouthful there, sister, but then again... do not expect most couples to embrace all of the definitions of swinging. Many would rather pick and choose the parts they believe in while trying to marginalize those they do not. As you correctly point out... swinging, in its primary and purest definition, is recreational, no-strings-attached sex between consenting adults. Period. No mention of couples vs. singles, commitment, faithfulness, friends first, any of that.
Now, beyond that broad definition are many, many, many variants. The variant subscribed to by lots of the folks around here is couples who exchange partners, or "wife-swapping," to apply the more sexist term. Does that mean their way is the only way? Absolutely not, although they would have you believe that it is. Does that mean you're in for a cyber version of stoning whenever you expouse something different than that ideal around here? Perhaps so.
As to the topic and your original query, I actually agree with a couple of other posters that your relationship with this guy is probably doomed. Even if he says he is ok with you stepping out and not having knowledge of it, it's simple human nature that ultimately he'll feel left out and resentful of your activities. You're probably better off in the long run to seek out a long-term relationship with someone whose personal values are more in line with your own.
Swinging on your own, as a single female without the encumbrance of a non-participatory partner will then become less problematic and viewed more positively, simply because a potential cause for drama has been eliminated. (Do not, however, presume that you'll be any more welcome around here as a single, un-attached female than as a single, "cheating" female. Response from other members toward me has ranged from polite acceptance to overt disdain, with a definite bent toward the latter.)
All the best to you, whatever you decide.