A jocular or mildly euphemistic variant of a dismissive retort meaning 'too bad' or 'that's your problem,' often expressed as 'tough tuchus' to imply 'tough butt' or 'deal with it.'
Examples:
EN: And secondly, I'm the attending, so tough tuchus.
ES: Y segundo, yo soy la médica de guardia, así que se aguantan.