watch for deer

Midwestern for: I love you

Him: "Heading back from the cabin, see you in 3 hours"... Her: "Watch for deer..."

Watch out for deer

An expression used by Wisconsinites, and Midwesterners in general, meaning "I love you", from "I love you, stay safe", popularized by the comedian Charlie Berens

"I'm headed to the Kwik Trip"
"Ope, it's snowing like the Dickens. Watch out for deer."