I (36m) just found out that my brother (32m) is actually my fathers illegitimate child. My mother is trying to keep it a secret but I think my father should know. I also feel betrayed that my mother hid this from me for years and that my brother is not my “real” brother.

My (36m) mother just dropped a bomb on me and I don’t know where to go from here. I have a younger brother (32m) and we were always close growing up. I never remember him acting differently or my parents treating him differently. I did notice though that my mother and father had an on and off relationship with my brother. It would be good for a while and then they wouldn’t be speaking. This went on for years but I also remember having fights with my parents so I thought it was normal. <br><br>What also stuck out was that my father would call my brother Richard, my mother called him Richie, and everyone else called him Rick. <br><br>I recently asked my mother why my father always called my brother Richard. She started to cry and told me that my brother is not biologically my father’s son but rather her ex-boyfriend, who was named Richard. She said my brother was born before my parents got married but my father said he would raise my brother as his own as long as my mother never told anyone, including me or my brother.<br><br>I was devastated. Emotions just all over the place. She saw I was upset and tried to reassure me that my brother is my brother and that I shouldn’t tell my father. She said she knows I have a hard time lying and that if I told him she would be devastated. I left and called my wife to tell her. She was also upset and thought it was weird that my mother didn’t tell us for years. She said there was no reason to keep it hidden from us and that it is a lie and secrets destroy relationships. She thinks that I should tell my father but she also thinks my mother should have told him herself. I am also feeling weird about my brother. I know he can’t help that he isn’t my biological brother but there is something that feels different. I don’t know if it is me rationalizing but I feel like I should tell my father. <br><br>What do I do?