Friend keeps touching my wife's feet

My wife has nearly perfect size 6 feet. A friend either touches them or pretends he will every time he comes over to the house. Sometimes she will have her feet extended on a foot stool and he will walk by with his fingers just inches from gliding across her sexy toes. Or he will bump her feet with his hand to say he's wanting her to listen for a second. Or he will quickly tickle her feet as a "joke". I love my wife and love her perfect little feet. I am both jealous and turned on by my friend touching her feet all the time.