More often than not when you have sex with a friend, it goes on more than once .
This is perhaps the most important thing to understand about this "problem".I put problem in quotes because it depends on what led to the sex.People don't just decide to have sex after being friends for some time. In fact, if that happens, it most likely means that they fell in love. And they don't usually fall in "ordinary" love; they fall DEEP because they have known each other well enough. So, the idea of setting boundaries after the sex is mistaken.So, to the question, I'd have to say NO.