Demi Lesbian is when someone is demisexual and a lesbian. A girl who doesn't experience sexual attraction to another girl unless they form a strong emotional connection with her.
Him: I'd do her. Would you do her?
Her: She'sbeautiful but I'd need to get to know them before I'd even consider that. I'm a demi lesbian.
A reply to a thread on 4chan's /v/ board about the Wiigame The Conduit. Due to it's complete and utter lack of coherence, and therefore high comedic potential, /v/irgins jumped on it and began to spread it across the rest of 4chan and Youtube. Extensive research has ended with this meaning (from knowyourmeme.com):
Original:
“Has anyone really been far even as decided to use even go want to do look more like?
Rephrased:
“Has anyone really decided as to even go that far in wanting to do to look more like so?”
Deciphered:
“Has any video game company really taken such measure to make a game so realistic?"
When you don’t want to call him a fiancé to your friends and he needs a bit of pandering to, like he’s a Demi-god.
Meet Craig, we’re engaged to be married, like, he’s my demi-husband / Dave’s such a Demi-husband: he can rustle me up the most divine hangover cures known to womankind.