>>58266>fictionalright, because if you're just interested in the abstract concept you'd totally write stuff like "I want her drunk without her knowing it"
so let's make one thing quite clear: you're an absolute asshole and utter shitbag for intoxicating another human being against their will.
since you're going to do it anyway - let's apply some harm reduction. i'm gonna assume she doesn't drink at all, since you see no other way of getting her drunk than to sneak it in. for fuck's sake, *don't* assume she can handle alcohol like you! start with very little alcohol mixed in. otherwise you'd run danger of straight-up knocking her out, making her projectile vomit all over your place or making it super obvious to her. once the world starts spinning and the words start slurring, she'll freak out and want medical attention (for her - leading to police attention for you shortly thereafter).
the quantities of alcohol needed to get an inexperienced drinker just a little tipsy are so small, it really should be no problem hiding them. sweet drinks are notorious for hiding their alcoholic content, because they taste good on their own. you could also use some fruity liquor in a pudding or jelly or some other dessert. goes well with fruit themselves, since fermented fruit are alcoholic. some alcohols have a strong (often herbal) taste of their own that makes it non-obvious, like absinth.
also: don't fucking do it.
if you don't hate this person - it's not worth the huge change of this incident absolutely ruining whatever relationship you have. if i even suspected someone would have done this to me, they'd be absolutely dead to me. fuck that shit.