Reality check: even in couples who participate in adult nursing relationships, the likelihood of one partner lactating (it can be two women) is minuscule. Most is dry nursing/dry sucking.
The vast majority of it is postpartum.
Relactating is a huge effort.
While milkmaids exist as a form of sex work, encountering a woman keeping up a milk supply and randomly hooking up is almost impossible.
The nutrition, hydration, supplements, off label medications, physical pumping and other things needed to bring in and keep a supply is daunting.
There’s a reason I think nursing mamas should have paid leave and social support above the poverty line.
To do the above post weaning, especially years later, is asking a LOT from a partner, much less random people.
The hucow fetushists can fuck right off, into the abyss.