Isbtfs Share definition Flag Stands for "I swear by the fucking stars," used while texting.It is used similarly to istg, which means "I swear to god." "Isbtfs, next time she says something like that I won't restrain myself from yelling at her" Isbtfs by <-worm-> June 3, 2024 0 0 Get merch Get the Isbtfs mug. Buy Now — $32.95 See more merch
