Navigating Personal Relationships

How do you navigate personal relationships where loved ones might get the idea that, because you are a therapist or pursuing that career, that you are now effectively THEIR free therapist. What do you do when they come to you, and ask you to help them process their emotions, or if they just start venting all of their stuff to you? What if the relationship starts to feel one-sided, where it once was mutually reciprocal?