United Kingdom, Oct. 10 -- Sienna Miller has opened up about her "bohemian" approach to breastfeeding while slamming those who have an issue with her "whipping" out her "boob" whenever her baby's hungry.

The 44-year-old actress is a mother of three, having welcomed a boy with fiance Old Green in May, and told Harper's Bazaar magazine that she has no problem stripping off if he needs food - regardless of where she's with, or who she's with.

Sienna said: "When you have a baby and you're breastfeeding a baby which I still am, hence the brain not here.

"Well, the respect for your body for your body, in my case, became enormous.

"And then if your body is feeding your baby and people have an issue with your boob, it bothers me because it's ...