United Kingdom, Sept. 10 -- Jennifer Lawrence has jokingly threatened to leave Instagram - just hours after posting for the first time.

The Oscar-winning actress joined the social media site and shared her first video on Thursday (10.09.26), in which she filmed herself as she said in her typically deadpan style: "So yeah, I'm giving it a shot and if anyone says anything negative I will quit immediately no questions asked.

"If anyone thinks something mean, I'll know. I'll know. And I'll quit."

Jennifer then posted on her Instagram Story, adding: "Please be mindful that any mean or aggressive comments can negatively affect the baby."

Hilariously, Jennifer - who has two sons with husband Cooke Maroney - then added: "It's me. I'm the baby...