Dakota Johnson has sparked rumours she’s engaged to Chris Martin after she was seen sporting a large ring.The 50 Shades of Grey star, 31, was seen wearing a large emerald ring on her wedding ring finger while shopping in West Hollywood, Los Angeles last week. Dakota, who has been dating Coldplay frontman Chris, 43, since 2017, wore a long black coat and a pair of grey jogging bottoms as she stepped out in LA, in photos obtained by Mail Online.