Found out my long time crush is dating...

I never said anything about the relationship being insignificant, I said specifically that I find it less of a problem emotionally. Advocating for OP to go after both girls has always been a joke (presumably by everyone mentioning it, but I'm not in their heads), if you can't tell. Even if OP doesn't want to break them up, having him in the picture requires split attention from the girl in the middle, and man or woman, no one is going to stand for that.
Even if some of us had been serious, I expect OP to know better than to take advice from Shenanigans posts.
On the other hand, I'm genuinely envious of his situation for the reason mentioned.

Fair enough good sir, I seem to be forgetting that is shenanigans.