I'll be honest--I don't think this is really about "boundaries" because boundaries are not rules that one spouse makes to enforce on the other spouse. Boundaries are fences that you put around yourself to decide who and what you will allow access to YOU. Boundaries are about YOU controlling YOU--not you controlling your spouse or your spouse controlling you.
So since you are not really talking about "boundaries" here but more like "Rules" to which you both agree (and even agreement can be ambiguous, because as you have seen, a spouse can agree in definition and then justify why they have to break the "agreement" or claim they didn't "understand"), let me share with you the agreement that my Dear Hubby and I have regarding friends of the opposite sex:
We agree to give 100% of our affection, loyalty and companionship ONLY TO OUR SPOUSE. There will be no affection given (in a romantic way) to any other person, same or opposite sex. There will be not loyalty given to any other person, same or opposite sex. There will be no companionship given to any other person, same or opposite sex.
Now before you object with something like "What about your children or relatives?" or some exclamation about being loyal to your job or church, let me say this: of course you give affection to your own children, and of course you love your siblings, parents, aunts, uncles and cousins--but that is "family" love, not romantic, intimate knowledge kind of love. Of course you are loyal to your team or company--that is not intimate loyalty. That is not what our rule is talking about! Our rule is talking about doing affectionate things with someone other than your spouse, to whom all of your intimate affection is due; it is NOT yours to give away, but theirs! Our rule is about loyalty to your spouse, your marriage, and you vows--always having your spouse's back, always standing up for them, and always considering them in all things; it is not yours to give away, but theirs!
And our rule is about giving to your spouse and only to your spouse, the joy of recreation, kicking back, having fun, enjoying yourself; it is not yours to give to someone else, but theirs!
And since MAJ nothing personal, but since the dynamic of your marriage is so far from even being able to comprehend that, much less being able to enact that on a mutual level, I doubt I'll respond again...and it's not because I'm a jerk. It's because you can not and/or do not hear us.