Plot summary
Bonnie is excited to meet Adam's best friend Mitch ( Bradley Whitford ) and his wife Leanne ( Nicole Sullivan ) who are coming to town to visit Napa wine country. But the two turn out to be hardcore partiers and never leave Bonnie's place after getting stinking drunk. Leanne also reveals that she slept with Adam multiple times before she met Mitch, something Adam never told Bonnie. Title meaning: An excuse Mitch uses to grope Bonnie's butt and a lie Adam tells about Leanne.
Credits
Adapted from Wikipedia contributors, Mom season 4. HTML formatting and reference markers removed.