What is mfw?

MFW stands for My Face When. It is a popular internet acronym used to express a reaction or emotion, often in response to something funny, surprising, or relatable. It is commonly used in online conversations or on social media platforms to convey a person's facial expression or reaction to a particular situation. MFW is often followed by a description of the emotion or reaction, along with an accompanying image or GIF to further depict the facial expression being referenced.