Liev Schreiber  bike son helmet ice pack shorts

Now this is a hands-on celebrity dad!

Liev Schreiber hit the streets of Brentwood to teach 5-year-old son Sasha how to ride a bike, but the actor had his elbow bandaged up. Let's hope he didn't take a spill.

Looks like mom Naomi Watts was spending quality time with the couple's 4-year-old son Kai. Lucky boy ... he got mom all to himself.

Love this happy family!