Show him you’re listening with this tip…

If he’s mentioned an interest to you in passing…

“What was that ________ you were talking about? I wanted to check it out.”

Examples:

“What was that Netflix show you were talking about? I wanted to check it out.”
“What was that restaurant you were talking about? I wanted to check it out.”
“What was that travel site you were talking about? I wanted to check it out.”