Just realized the theme..
when Patrick Dempsey was dropped off at the airport at the end of the film, again we see the image of the Three Graces dominating in the background and it hit me, the three sisters were the Three Graces: daughters of Zeus that represented all that is beautiful, noble, and pure: or Beauty, Mirth, and Good Cheer.
I haven't had time to look for further symbolism in the film, but now I'm intrigued..there's more to this than a comedy/romance!
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"I'm sorry, but.." is a self-contained lie.