Cute: Ronaldo And Son Flex Muscles In Instagram Post

Ronaldo has shared a precious photo of himself with his son, Cristiano Ronaldo Jr., getting their flex on with matching white bath towels tied around their waists. The 30-year-old soccer stud and his 5-year-old mini-me make their best "tough guy" faces for the camera.

The Real Madrid star and his son have also been known to do a few crunches together. Hey, gotta make sure that your mini-me has a mini eight-pack, right? LOL!

PHOTOS: See more photos of Ronaldo and his son...