What's he mean by "spill some tea?"

Native speaker’s answer
Rebecca
"Tea" is a slang word for "gossip." So, when you "spill the tea," it means that you are sharing the gossip. When we gossip, we are talking about other people, usually involving details that are not confirmed as being true. Ex: Spill the tea! I want to hear all about your date. Ex: I can't believe she spilled the tea in front of all of our coworkers.