Leading the fashion scene is Mary-Kate Olsen. This week, the Bridgehampton resident and co-founder of The Row was seen clutching a brown paper bag and an Amex black card on a grocery run.

Fashion designer and former child star Mary-Kate Olsen is apparently summering in the Hamptons, and she's doing so in the most low-key attire possible: sweatpants.

Mary-Kate Olsen, the co-founder of the coveted label The Row, looked very different in a rare outing in the Hamptons – see pictures.

Mary-Kate Olsen—who, along with twin sister Ashley Olsen—prefers to stay out of the public eye, stepped out for a casual stroll in the Hamptons June 29.

Mary-Kate Olsen was spotted out in the Hamptons, looking casual in an oversized tee and sweatpants while at a local farm on Sunday, June 29.

Mary-Kate Olsen stepped out in the Hamptons for a rare public appearance in a decidedly casual ensemble.

Mary-Kate Olsen demonstrated exactly where The Row’s flip-flops should be worn: on a lavender-scented grocery run in the Hamptons.

Mary-Kate Olsen keeps a relatively low profile since stepping away from Hollywood The fashion designer was spotted making a rare outing in the Hamptons During the Sunday, June 29 outing, the former ...

Mary-Kate Olsen was spotted in the Hamptons on a rare outing wearing sweatpants. The former child star is notoriously private and rarely steps out in public. Olsen founded The Row with her twin sister ...