If you mean the love potion, you can give it to the shopkeeper and hayden iirc, but using it on them will drop their relationship a certain amount each time that happens, and i think Hayo is a male, but i don't really know about it, Hayo next focus seem to be the Rats in the basement in the tavern based on that pic on twitter or patreon, but it might also include other things, like making the amount of time you craft a recipe before it is added to the mastered list for each of them lower.