Asking in-laws to wear mask at home when interacting with baby?

When visiting in-laws and parents with baby, do you let them interact with baby without them wearing mask in their own home? Or do you limit their interactions in any way? Do you let them carry baby when they are still wearing the clothes they wore outside whole day at work? If you have any concerns with them interacting in the above manner, how would you politely tell them that when they feel they are the boss in their own homes? Daily covid cases are 500+ now, and may rise to 1000+ soon, according to reports. Can't completely cut off visits to their places unless circuit breaker. Am concerned (they work at market & hawker centre) but don't know what to do.