There's no difference between doing something like this and, for example, slipping a box of tampons into a male friend's bag of purchases at a store, leaving it visible of course, without him noticing it before he tries to hit on some girl. Heck, if you get it on sale it's cheaper than a lot of other things you can do to irritate people and you don't even need to be in the same neighborhood much less town, city, county, state, province, country, or even continent.
Stop complaining. I could have done this more painfully. - Dryad from Sacred 2.