It makes sense to me. Her somewhat clingy persona, constant bids for attention and absent-mindedness? It all adds up.

Fleur clearly has some sort of anxiety complex. Fancy's the only stallion she's met who treats her and others around them right and it's quite likely she's had bad experiences with others in the past. She's terrified of losing him or disappointing him. It's like Rarity's obsession with impressing him but more so.

Perhaps it's his curse. He's so pleasant that he makes ponies go too far in wanting to please him.

Maybe I'm going off on one but there's a lot of potential for very complex characters in Fancy and Fleur. I'm surprised they don't get more attention from the show and fan-base.

Well done in this case.