Two and a Half Men S02 E19 A Low, Guttural Tongue-Flapping Noise

"Two adults. One kid. No grown-ups."

After Charlie takes Alan to an eye doctor, they end up at cafe where they bump into Charlie's ex-girlfriend, Sherri. While there Alan shows an interest in Sherri, and decides to ask her out. The problem is that Alan can't get over Sherri's relationship with Charlie.