My Story...possible "grass is greener" scenario?

[Gardener]

nsw1222,
Quite frankly, she is cake-eating her way through the entire bakery.
And setting you up and jerking you around right and left.

Thats one reason I think she decided to get birth control.

C'mon! You 'think'?

She asked me if I couldnt see the possibility of how her being with someone else might make things better between the two of us

classic cheating cake-eating WAS BS.

But I also asked her if she would give me the same chance that this other guy has

So you're asking her if you may compete w/OM for your wife?

She actually responded better to that, saying that she didnt have intentions of being unfaithful (having sex with the other guy) but that again she wasnt going to make promises and whatever happens happens. She said something to the effect that she didnt know if she and I would have sex either but if it happens it happens.

Of course, unfaithful sex "just happens". She's telegraphing her intentions in no uncertain terms and you're not getting it.

So from my side I was pushing "keep an open mind" and "give me the chance that the other guy is getting", and from her side I was getting the no promises and "whatever happens, happens"

Sorry, guy, you were pushing the, "I'll be a doormat," From her side, she was walking all over it and wiping her feet.

Did I set her up for ultimate cake eating

No, she's already doing that. You said "okay" and gave her permission.

Valentines day is coming up...should I send flowers and make a big deal?

Ignore Valentines Day.

Or is this positive change? Are we a step closer to reconnecting? And what do I do? Should I start pursuing her?

I don't even know what to say, here.
Sorry to be so blunt. No, actually, I'm not; you need it.
Have you even read DR? Go read/reread DR, especially LRT section. Read more posts here. I don't think it is possible to do more wrong things in a sitch than you are doing, frankly.
Good luck,