Hilary Duff glasses plaid louis vuitton jeans hunter boots baby luca Who knew they were friends?!

Hilary Duff and son Luca had a playdate with Jack Osbourne's wife Lisa Stelly and daughter Pearl yesterday, and we were surprised to see them together considering we weren't aware they were pals!

Hil matched with her little boy in a plaid shirt, while Jack O's wife kept it basic in black.

We wonder if Lisa cut the baby bonding session short when she caught word of her sister-in-law Kelly Osbourne's seizure and subsequent hospitalization?