What you say to your friend, Alyssa, when you are mad, frustrated, annoyed, stressed out, et cetera, et cetera, et cetera. Soon thereafter, it is realized that this is very similar to "shitless" and you explode into fits of giggles. SHITS AND GIGGLES!
BFF 1: "Oh SHIT LYS I forgot to take my birth control!"
BFF 2: "That is very shitty."
BFF 1 & 2 (together now): "Hah. Hah. Hah. Haha."