Eh, this is something you really should check with a pediatrician or orthopedic doctor soon, especially since your little one is already almost two, they can assess whether it's tight calves, muscle imbalance, or just a habit he'll outgrow, but better to rule out anything that needs early intervention. A few of us mum friends have kids with similar quirks, and some turned out fine on their own, but one mum friend's daughter needed some gentle physio exercises that made a big difference, so it's best to get a professional opinion first!