Joaquin Phoenix and his fiancé Rooney Mara are seen with their newborn son River in LA

Joaquin Phoenix and his fiancée Rooney Mara look every inch the doting new parents on stroll with baby boy River in Santa Monica

Joaquin Phoenix and his fiancée Rooney Mara looked every inch the doting first-time parents as they returned to their Santa Monica home on Friday. 

After running errands as a family-of-three, the 46-year-old Oscar winner could be seen cradling his precious baby boy River. 

Keeping a low profile, the Joker star wore a black t-shirt, matching beanie, sweatpants and a face mask amid the ongoing COVID-19 pandemic. 

Proud dad: Joaquin Phoenix and his fiancé Rooney Mara looked every inch the doting first-time parents as they returned to their Santa Monica home on Friday

Mara, who gave birth to their son in September, rocked a striped shirt, beige cardigan an Converse sneakers.   

Earlier in the day, she was responsible for holding their infant, who was dressed in a green and purple tie-dye shirt and striped pants. 

As they walked across the street, Phoenix stayed close to Mara’s side as she toted a large bag and kept her brown tresses in a low bun. 

Quality time: After running errands as a family-of-three, the 46-year-old Oscar winner could be seen cradling his precious baby boy River

Quality time: After running errands as a family-of-three, the 46-year-old Oscar winner could be seen cradling his precious baby boy River

Family-of-three: Keeping a low profile, the Joker star wore a black t-shirt, matching beanie, sweatpants and a face mask amid the ongoing COVID-19 pandemic

Family-of-three: Keeping a low profile, the Joker star wore a black t-shirt, matching beanie, sweatpants and a face mask amid the ongoing COVID-19 pandemic