I drove past Wendy’s the other day. No other stores were open, so I asked, “Wendy’s openin’ then?”
Wendy's Openin'
Explanation
Explain Bear
Listen up, buttercup. The joke is that "Wendy's openin'" sounds like "when is opening?" which the author asked, since Wendy's was the only place open. I bet you also think the earth is flat, huh?