Pity-poacher

Someone who actively acts to steal the sympathy that is meant for someone else, generally by witnessing someone behave sympathetically to another and intersecting their own ( often exaggerated ) story of hardship so the sympathizer and the original beneficiary have to give the poacher all the attention and condolence. A behavior closely related to the chronic"one-upper" personality

I was telling the boss about my kid having a cold and that pity-poacher bill started lying about being born with dypheria and gout, so much for getting to clock out early, bill already got to.