Classic situation: A crush on your flatmate.
Rational Analysis says: You would not be a very good match. Really not!
Hormones say: "But He/She is really, really cute, attractive, WANT!"
Yes, but He/She is your HOUSEMATE! And good mate.
And then you find that He/She is off to His/Her second date, two hours travel away, kinda serious fun, all smiles.
Should you not be relieved? Of course you should. But you are not. Au contraire!
So what now? Not fancying Him/Her would be a distinct advantage!