The England striker signed for the Hoops just a few weeks after his eight-year-old son Mace was snapped up by the West London club.
He said: "He joined the Academy shortly before I came to the club.
"He was really pleased when I signed for QPR as well.
"He's enjoying his football and learning fast. He came up to me last week and said he wanted a goal bonus. So I agreed to give him £1 for every goal he scored.
"Then he went out the following week and scored a hat-trick!"