Antonyms for "picking up the check" include "leaving the bill", "ignoring the payment", "neglecting the expenditure", and "abstaining from the expense". In social occasions, not picking up the check could be seen as rude or impolite, but there may be situations where it is not necessary or appropriate. For example, if the guests are equally wealthy or the cost of the meal was low enough. In a business setting, it might be expected that one party covers the expenses, but in some cases, it could be seen as a bribe or a conflict of interest. Whatever the circumstances, it is important to consider the context and cultural norms before deciding whether or not to pick up the check.