Originally Posted by borntoquilt
I am sure you are not the only "friends" these people have over so other friends are experiencing the same behavior. Send them a dog obedience book with a bookmark in the appropriate chapter. Hopefully, they will get the hint. Also use their address for the return address. They will never know who sent it!
Make sure you send it from an out-of-town post office, too, so it isn't postmarked anywhere near your house!
If they figure out it was you that'll be end of the friendship, so I'd be extra careful with this one. ;)