"Today we will be brewing Amortentia, each of you will add two drops of your own saliva five stir’s after the last step written in your books. Of course adding bodily fluids of the potions creator renders the potion useless to anyone who isn't destined to the creator, soulbonds might be a term you're familiar with. Therefore they should all be safe for us to be around." Slughorn was weaving through the tables as he spoke.