Well they only showed us a couple of evenings but apparently the relationship has been going on for months so a declaration of love is plausible. Just felt out of the blue since the viewers weren't treated to the progression of the relationship.

I doubt that 'do anything for her' is any more than writer hyperbole at this point. If s10 turns out to be the last then it might have more meaning. Perhaps a foreshadowing of what will happen to the Morgan character at the end of next year.