A sacrificial lesbian, is basically your very good friend who may identify as not-straight to some degree, while as you during the day in direct sunlight are completely heterosexual. Yet during the night, usually in the presence of being under the influence, do you take your not straight friend and make out/ hook up with them for the sake of zero fucks being given. All heteronormativity returns back to normal the next morning.

Sometimes done for the fun of having a chill person to make out with, sometimes used as a tactic of twat swatting one another.

When you eat dirt for the first time and leave your family to build a shack in the woods