A little message to pass along? A nice picture between friends to share? A wink to tease them?
Why don't you send them an offbeat postcard?
They probably have a fridge on which your card will find a place of choice. Unless it is quickly hidden in their bedside table. ?
Embellish your card with a playful theme, add a touch of humour with a small offbeat message on the photo and you're done. With this offbeat postcard, the effect is 100% guaranteed at reception.