Mo-Ho is a new synonym for Fag Hag and Fruit Fly and is gaining popularity within gay/gay-friendly communities.
Mo is short for Homo
It is common for females to dislike being referred to as a Fag Hag because typically Hags are old, ugly, and wrinkly. Fruit Fly is also disliked at times as it is homonymous with insects of the drosophila genus (i.e. drosophila melanogaster)
Anna - God, Rachel...you're such a fag hag!
Rachel - I am not a hag! I am a moho. Get it right, tool!