May 15, 2012 No Comments FREE M&M’s at Thorntons Stores Print out the coupon and redeem for a FREE Standard Size M&M’s Any Variety at Thorntons stores. Coupon valid May 15-214, 2012. Locations. FREE M&M’s at Thorntons Stores -EXPIRED Facebook Twitter Add Comment Notify me of follow-up comments by email. Notify me of new posts by email.