SAFTB is a phrase used to signify Saturday as a day just for “hanging with the boys” and engaging in male bonding without women to “bother them” or to pull them away from their bros. It's generally used in jest and has become, in its own way, a meme.
About Barstool Sports: they are an American blog website and digital media company headquartered in New York City that produces content on sports and pop culture. It was founded by David Portnoy in 2003 in Milton, Massachusetts; the CEO is a bright, hockey-playing woman named Erika Nardini.
Barstool tests the limits of a norm we currently refer to as “cancel culture." They don't buy-in to political correctness and they do it with American humor. They have a tremendous following on podcasts, college campus' across the country. Their sense of humor is captured in all their merchandise- boys and men love it... A large part of Barstool’s success can be attributed to its popularity on social media. Perhaps the best example of this is the phrase, “Fridays are for the men. Saturdays are for the boys.”