you can start lactating without being pregnant. like, if you stimulate your nipples enough (non-puerperal lactation induction). even people without boobs can lactate. also, are u saying that by drinking alcohol and then drinking someone else’s breast milk, that you would somehow alter the breast milk? because that’s not true. it’s considered generally safe to breastfeed from your partner even while they’re breastfeeding a baby (unless you have an contagious disease like thrush).