Bedroom sharing. Thoughts on this?

My ex and I never went the legal route ( I will be starting the process this week ) We originally did 50/50 then he wasn’t in a financial position to do that so I have our child full time and he was to see his dads on weekends. His father is dating someone now (who is lovely to our child) however, the living situation at his fathers is far from ideal. It’s a small 1 bedroom apartment. My child’s uncle rents out the bedroom and my ex uses the living room as a bedroom/living room. I recently found out that my ex, his gf and my son were sharing a bed. I immediately cut off sleepovers and he only visits during the day and comes back home to sleep. What are the laws on this? I do not believe it’s okay they all be sharing a room. When it was just our child plus dad sharing, it is what it is and our housing market is shit. But to add another female adult and having them sharing a bed is not okay with me.

We live in Ontario, Canada. I’m just wondering what the rules are for bedroom sharing like this?

Thank you for taking the time to read.