Your question cannot be answered since Peter is not married to a man named Louis.
Please rephrase your question so it can be answered properly.
There is no such episode seeing that there is no character on Family Guy named Louis.
Your question cannot be answered as there is no character of Louis on Family Guy.
the episode when peter and Louis get Chris and Meg a boyfriend/girlfriend
Season 2|Episode 13 Road to Rhode Island
Season Three's Stuck Together Torn Apart
Peter Kay was in the episode Love & Monsters.
There aren't many but ...GiggityWhat the deuce?Who's leg do you have to hump to get a dry martini
Mia dumps Peter in the first episode of season 9
Season 2|Episode 8 I Am Peter, Hear Me Roar
Just dance cona be OK
Peter, Peter, Caviar Eater
Season 3|Episode 14 Brian Wallows and Peter's Swallows