When you do this, it has to be they are constantly using you. If there have been times you have leaned on them, and they gave more to you than you gave to them, it’s now your turn to be the rock. You cannot just use someone and then not be there when they need you. Well, you can, but that just makes you an asshole!
How many times have you been in a heated discussion with a partner and you’ve said some things that you probably wish you hadn’t, or did something you could not take back? This is reacting to a situation and not responding. Reptiles do this as well, as they do not know any better.