trifle
/ˈtrī-fəl/
noun
something of little value, substance, or importance
a dessert typically consisting of plain or sponge cake often soaked with wine or spirits (such as brandy or rum) and topped with layers of preserves, custard, and cream
verb
to treat someone or something as unimportant
to talk in a jesting or mocking manner or with intent to delude or mislead
to handle something idly
phrasal verb
to treat or deal with (someone or something) in a way that shows a lack of proper respect or seriousness
You shouldn't trifle with their feelings.