This porn video tag is referring to a specific type of content within the LGBTQ+ community, focusing on homosexual interactions between men. The use of "fat" in this context may refer to either the physical body type of the individuals involved or could be an indication of their personalities. It's important to note that this tag may not have a direct translation into English and can vary depending on regional slang or local language variations.
The term "gay" is used as a label for content featuring homosexual interactions between men, and is widely understood in the English-speaking world, regardless of regional differences.