Say "its not a competition", or tell them, sincerely or otherwise, that "in life, when someone mentions an achievement, its common courtesy to not immediately talk about yourself". Make them look socially mal-adjusted and they may realise that the attention they get from their one-upping is not of admiration, but of mild disgust.
FloorSweets t1_jaeifur wrote
Reply to LPT Request - how to respond to people who constantly try to one-up you and diminish your accomplishments? by idkifik
Say "its not a competition", or tell them, sincerely or otherwise, that "in life, when someone mentions an achievement, its common courtesy to not immediately talk about yourself". Make them look socially mal-adjusted and they may realise that the attention they get from their one-upping is not of admiration, but of mild disgust.