I adore both of these characters so put them together plus UST plus backstory plus wit plus great writing? Um, YES PLEASE! I love how Greg's fit into society and how he's so blunt, realistic, and matter-of-fact. I love Marietta's strength, her vulnerability, and especially her amazing backstory. I can never get enough of her-- there's so much more going on that tunnel-vision-martyr-emo-15-year-old Harry doesn't see and that spell was one of the first of many questionable things we see Hermione do to protect those she loves. (I for one love her ambiguity and the fierce darkness, though I can't approve of many of her choices)
I loved the build up, the misunderstandings, Marietta's reaction to Greg's finite incantatem, and the very delightfully sexy and sweet resolution of it all.
Wonderful story full of all the good stuff I love-- I'll just be over here loving you from afar! :)