Parental rights in just testing

You don’t all know the details but my sis and her husband have not been in love for at least 3 years.

They are staying together to raise their child and the convenience of keeping the house they bought only 4 years ago.

I’m not saying it’s right, it’s just where they are right now.

I’m asking about parental rights because the dad has a bad habit (that only seems to be increasing) where if he takes their child out alone he doesn’t want to tell the mom where he is.

I don’t think the child is in danger with him, I think he’s doing it just to piss off the mom and make her worry.

For example, Sunday the mom had to work. Mom and dad both often work weekends in their line of work. So dad told mom he’s taking their kid to a festival that afternoon.

That’s fine.

When mom got home in the evening, they still weren’t back so mom texted dad to ask where they were, when they’d be home.

He wouldn’t tell her.

Mom wanted to meet with them to spend time together. Dad said no.

Dad didn’t come home with the child till 10 pm and wouldn’t say where they had been.

They are legally married. He is the bio dad. So he basically says he doesn’t ever have to tell the mom where he is with his child.

Is that true?