Dan's never been one to chase after what doesn't belong to him - he knows better. He never had a chance with Casey, since before he even met him. He's married to Lisa, and if it weren't Lisa, it'd be Dana, and Dan would always come in at distant third to them if it ever came down to it. Really, Dan's content with being the best friend, the on-air partner, the voice of reason (or something like it), and adviser of what is cool.
But he still can't help but think what it'd be like, if Casey ever were to kiss him.