All Loki would imbibe was milk from the Aesir’s golden herd, thick and creamy, which he let run down his chin just to taunt Thor. He’d often find himself pushing Loki down onto the milking chair and licking him clean, and then cursing himself for falling into Loki's trap. For Loki was a trickster, and no matter how much Thor tried to hold himself back - leave him unmilked for days at a time so he'd be begging for it - he always gave in.