Naughty, naughty.

Hilary Swank is eyeing up to play a Manhattan attorney who becomes romantically involved with her best friend’s fiance following her 30th birthday in Something Borrowed, an adaptation of Emily Giffin’s debut 2005 novel which Swank will also produce via her 2S Films Banner.

Giffin also wrote a sequel titled Something Blue, whose rights Swank have also nabbed.

Warner Based Alcon Entertainment will finance.

The project is out to writers according to Variety.