put on a brave front
1. To appear or make oneself seem more courageous, resolute, or dauntless than one really feels. I could feel my knees shaking with terror before my commencement speech, but I put on a brave front and stepped out onto the stage to deliver it. This girl I'm dating has a big dog that I'm really scared of, but I'm trying to put on a brave front when it's around.
2. To react to or face difficulties, setbacks, or adversity with high spirits or good cheer. John's been putting on a brave front ever since his wife left him, but I can tell that he is devastated on the inside. I really didn't want to spend Thanksgiving with my wife's parents, but I put on a brave front and suffered through it with a smile.