Proud Mommy Trainer

I'm a personal trainer who's also into DDLG. When I work out with my sub, it feels natural to encourage and discipline him like a supportive mom would. We lift heavy together but if he slacks off or doesn't push himself, I remind him firmly that I expect the best effort - sometimes even in private messages with some teasing about being lazy. Is this just part of pushing boundaries as partners or does something seem off? Would love to hear what others think.