In What If? Vol 2 60 (the Wedding Album issue), there are multiple alternate realities and one of them features Jean falling in love with Warren instead of Scott. I think as a result Hank becomes the leader of the X-Men instead of Scott so he angrily defects to the Brotherhood (reminds me a bit of Ultimate X-Men's opening arc).
But yeah, it's funny how there were a couple of close calls between them in the 616 Universe and even in X-Men: Season One, but they usually never end up together despite being the original X-Men love triangle.