Good point Phee, that Regina is emotional and Greg did literally burn any bridge there (with electricity!)
In all fairness, it was the other way around – Regina was the one to burn any bridge there by kidnapping Kurt, killing him and not be remotely honest or remorseful to Greg/Owen about that.
Regina’s whole attitude towards Greg Mendell the moment she realizes he’s adult Owen Flynn is so disturbingly cold for someone who once connected to him as a young boy and considered being his stepmother that it made me really wonder is that’s how she’d be treating Henry as a grown up if he kept his stance against Regina’s wrongdoings. That’d totally be character assassination for Regina, so I was very pleased to see the finale relieving me of this fear.
However, that doesn’t change the fact that, for all the greatness that was seeing Regina’s relationship to young Owen, the follow up with Greg Mendell has been a big letdown. Nothing that made Regina/Owen special carried over to Regina/Greg, not even Regina’s soft spot for him, so what was the point in spending a whole episode developing that? I feel this damaged any potential the character might’ve had, and it’s telling that the only thing I still expect to see from Regina/Greg is for her to throw in his face how big a hypocrite he’s been being pissy about her killing his father when his girlfriend essentially did the same to Henry’s (that they know of) and not only he’s not taking a stance against it but was also helping her to complet the job, killing his mothers and grandparents through the destruction of Storybrooke. After that he’s useless, and he could get a comical, black humor-like death for all I care.