Season 5 Episode 9?

Hi Everyone,
checking to see what the context of this episode really is.
some episode guides have the following description:
Christine convinces Lindsay that being single is the key to happiness, which prompts her to leave her husband and move in with Christine.

I however do not recall this plot and can't find this plot's episode online.
The episode I did watch is where Barb goes on a date with Dave (the immigration officer) with Christine being the third wheel, and things don't go well for them.

thoughts?