DDLB stands for "Double Decker Licky Biscuit." This term is used to describe a specific type of sexual act that involves oral sex. In this case, one partner performs oral sex on the other's genitals while simultaneously licking their anus. The name "double decker" comes from the idea of two layers being pleasured at once - the "lower deck" referring to the anus and the "upper deck" referring to the genitals. This tag is typically used in adult videos or descriptions that cater to a more adventurous and experienced audience.