The actor, who turned 40 in September, says his youthful appearance is disliked by Ava, his daughter with ex-wife Reese Witherspoon.
"My daughter hates it. Because sometimes people have thought I'm her brother, and she's freaked out by that," Phillippe told Variety.
The actor, who also Deacon, 11, with Witherspoon, is looking forward to the remake of his 1997 film "I Know What You Did Last Summer", which launched his career.
"I'm excited about it. It just makes me feel old.