Posting messages on social media websites through someone elses account, typically a spouse or whatever the gay equivalent to spouse is. You need not have an account with the social media site, but lurk on it under your spouses account. Sometimes you see something that just moves you to post, even though you are signed in under someone elses name.
Chance: I like that picture of your grandpa in a thong! (this is Lawrence lurkposting btw)