After seeing this image:
I have an interesting idea for a fic:

After seeing how well last Hearths Warming Eve went last year, Pinkie figures she should invite another friend this year, and since Fluttershy will be spending the holidays alone this year, She's the clear candidate. After all, Her family would love Fluttershy.......

She was right..... a little too right.
Thanks to events that happened during HWE, Marble, Maud & Limestone (and Pinkie herself) have fallen in love with Fluttershy (much to the dismay of said Pegasus)
Sister arguments, Logic-ignoring powers & choices ensue

EDIT: thinking about it, you could probably put Rarity, Twilight or Rainbow in place of Fluttershy, I just picked her because of the image

5213652 You shod post this here !

5213913 the idea isn't Polygamy, the Pie Sisters are being a little selfish.

5213962 k, sorry

5213962
5214105
Could be a good fic if it was polygamy as well.

5215196 And funny if Fluttershy is the "stallion" in the relationship(s). If you know what I mean.

p.s. Fluttershy is stell a mare.

5213652 No, Fluttershy is the perfect character for this! She will be super overwhelmed by all the romantic attention and the fighting over her that's going on and all.