How do I deal with a situation where someone else's child is misbehaving in my house and the parent says nothing?

This is a tricky situation! There are many parents who do not check their children in front of others so you maynot be able to judge whether the child misbehaves regularly or was it just that instance at your home. Maybe the next time the child comes over and the behaviour persists then speak to the parent. You will be able to judge from the parents reaction whether the friendship is beneficial to your child or not.