Stefani Tatavitto and Chrystal Klein, both 23 years old, started wet nursing each other's families nine months ago.
The mums from Connecticut, USA, are now encouraging others in their position to do the same.
Chrystal encourages friend Stefani to feed her 19-month-old baby whilst she works night shifts at a factory and believes it 'comforts' her toddler.
The mother-of-two isn't worried about her daughter Ariana forming a strong bond with another woman, despite Stefani feeding her up to six times a week; 'I don't think it's shocking to nurse another woman's child - breastfeeding is natural.'
'Because of Stefani wet nursing, I don't need to pump milk for my daughter or worry about her not having any milk.'
Stefani also enjoys the set up and relies on Chrystal stepping in when she wants to go out to socialise.
The mother-of-two said; 'You drink breast milk from animals, it's not that weird to drink breast milk from another human... if anyone has a problem with it I have not nice words to say to them.'
Neither of the women have received criticism from their families and friends, although Chrystal admitted her girlfriend was hesitant at the ideal; 'My partner was sceptical because she's unsure about what Stefani is putting into her body.'
Although Chrystal was eventually able to persuade her; 'We know Stefani has a pretty well balanced diet and she doesn't smoke or drink.'
The mums are well aware of the taboo surrounding their choice, especially as there is also a risk of transmitting infections, including hepatitis and HIV through breast milk. 'We were both pregnant at the same time and we were tested for infections and both of us were clear.'
Both Chrystal and Stefani believe that the benefits of their children 'getting milk from the tap' outweigh the negatives.