They met when she was looking for Chloe after she (Chloe) faked her own death. She found him in a cornfield after he came down with a bolt of lightning. She was originally planning to meet him anyway. She took him to the hospital and so on...
Also, it happened first episode of Season 4.
Stewie Loves Lois
Season 5|Episode 1 Stewie Loves Lois
I think after that episode of family guy buisness guy, peter gets amneisa and Lois tries to help him remember who he is, but when Lois see him flirting with a another woman she takes of with the kids. and this is quagmire's time to be with Lois
D-a-m-m-i-t Janet
The episode Deep Throats, it is Season 4, Episode 23.
The episode is "Stewie Kills Lois."
Whistle While Your Wife Works.
Stewie Loves Lois
Season 2|Episode 1 Peter, Peter, Caviar Eater
Baby I Love Your Way by Peter Frampton
Season 5|Episode 1 Stewie Loves Lois
Peterotica
I think after that episode of family guy buisness guy, peter gets amneisa and Lois tries to help him remember who he is, but when Lois see him flirting with a another woman she takes of with the kids. and this is quagmire's time to be with Lois
D-a-m-m-i-t Janet
Family Guy Viewer Mail, season 3 Episode 21
the episode when peter and Louis get Chris and Meg a boyfriend/girlfriend
The episode Deep Throats, it is Season 4, Episode 23.