K im not very good at stuff like this but got it into my head i HAD to do something.
I mixed up some nesquik chocolate milkshake power with water and smeared it on my mum's white pants (underwear not trousers).
I went in to her room this morning and was like "hey um...i found what you left on the bathroom floor last night and moved it so dad didnt see it" and she was like "what?" so i handed them to her and opened them and she was like OMG WHAT IT THAT! and after she'd been screaming about it for a bit my dad came into the room and was like "what are you shouting about?" so i pointed to the pants and said how I'd found them and he started like sniffing and licking them and she went mental. (He was in on it, not some sort of wierdo)
Not amazing but I had a giggle!