The 12th Fleet: Starbase Valhalla

The In-Game Fleet's, are those temporary, for completing missions, or do they last? Do you have to join one every time you log in? For some reason I just couldn't find the answer.

A fleet is tied to your character once you accept an invite to one.
In most games it even shows under your character like

.....Soda......
<12th Fleet>

You're always in the fleet and see fleet-chat until you leave of your own free will.

or get kicked for chatting up and sleeping with the admirals sister/girlfriend.

Tsori wrote:or get kicked for chatting up and sleeping with the admirals sister/girlfriend.

Look I already apologized, I had no way of knowing....