Baring all that in mind, I don't know if this is a good thing to pursue.
do you want to be when you pursue it? Or not pursue it? Either choice -- do you choose to do it with your nose clean or not?
- Could choose to not pursue and honor the present agreement.
- Or could choose to negotiate to change agreement, so you then can pursue honorably.
- Could choose to neither change agreement or obey agreement. Dating her dishonorably in a sneaky way.
- Could choose something else I can't think of yet. (Tired, my apologies. Late at night.)
I'd suggest letting it go or pursuing it honorably. Not this business of disobeying the limits of your agreement with your spouse and crossing limits.
Why do you do that? Why is HE breaking agreement things? If the agreed upon limit between you is expressing poly thoughts/feelings and mild flirting but not more -- what are you guys doing threesome-ing with her? Even as a "present?" This person is a person. Not a THING.
Engaging in sex with her also feeds the yen to HAVE more with her -- more sex, fuller relationship, etc. Which is what you cannot have under the present agreement.
This business of pushing/crossing limits -- it's not leading to anything but this fuzzy confused space that you do not seem happy to be in. So could choose firm it up one way or another and behave accordingly so you can keep your nose clean about it. I'd go with one of these:
- Obey your present agreement and back off the crush person.
- Change your present agreement so you can date the crush person honorably forthrightly and not all "messy."