You were pregnant, and you were in a room with a doctor and bucky was leaning against the door frame, listening

Medic:"When was the positive test?"

You:" A couple of weeks ago,"

Medic : "Date of your last period?"

You:"I...I don't know."

Medic:"Any idea when you conceived ?"

Bucky overhears and interrupts you

Bucky: "Come on darling, you don't remember ."

Bucky: "I hit it in the bedroom while your boyfriend (Steve) was on a mission." He says proud and smug