Actually, the subject came up a long time ago in TNG when Beverly Crusher started up a relationship with a symbiont in a male host. Well, fast forward to the death of the host, and transfer of the symbiont into a new host body, and first, shock, it's in Riker's body, and somehow that's ok, but then, the final host ends up being a woman, shock, scandal. The symbiont wants to continue, but dear Dr. Crusher chickens out.
no subject
http://memory-alpha.org/en/wiki/The_Host_(episode)
Ever read Ursula Le Guin's "The Left Hand of Darkness"?