selfish sibling

idk if it's normal or weird in general. I like it's selfish when someone vents to you, but when you try to vent to them they just ignore you. IT'S REALLY WEIRD AND ANNOYING!. So when ever they have a problem or as an example something happened that made them happy or sad. They will come to me and tell me. I'll just listen patiently. BUT!! when it come to me they will just ignore me and after that most likely i won't share that much to them and . They call me selfish or blah blah. it annoying