Sienna Miller is getting candid about being with a younger man. The Mississippi Grind actress, 44, opened up on Monday about her relationship with younger boyfriend Oli Green, 29. View this post on Instagram A post shared by Oli Green (@ooroosgreen) Speaking about their 15-year age gap, Sienna challenged the double standard that exists between younger women dating older men and older women dating younger men. She told Grazia: "I remember being 21 and auditioning to be the love interest of a 45-year-old man.