No makeup? No problem!
Taylor donned an oversize black hoodie with gray yoga pants and wore her hair in a low ponytail, while Selena paired a pink sports bra with black-and-white workout pants while attending a class at the Body by Simone fitness club in West Hollywood, California.
Though the "Bad Blood" singer's lips appeared dark, she was noticeably without her trademark red lipstick or winged eyeliner.
Apparently the longtime BFFs spent a lot of quality time together over the holiday weekend.
On Jan. 15, Taylor and Selena both took to Instagram to share photos of themselves goofing off in a giant bush.
"Are we out of the woods yet?" Taylor captioned her version of the silly snap, referencing her song "Out of the Woods."
"Are we in the clear yet?" Selena wrote in the caption of a similar shot.
But that's not the only reason why MLK weekend was particularly notable for the duo. T.Swift also had an adorable get together with her godson, Jaime King's 6-month-old son Leo, while Selena debuted her new romance with fashion sales and merchandising exec Samuel Krost.
What a weekend!