Breast milk curiousity

So, i was just curious......i am a 34, mother of 4 and my youngest is almost 6......my question is, how long can u produce milk? The reason im askin is because the other night my SO was messing around and squeezed my nipple and

Some milk came out. He has no kids and was just curious and since i had my tubes tide 5 yrs ago, breast milk isnt something i have thought about was was just curious how long it takes before u completely dry up? Im not worried about it, was just curious 😊