My MIL has been going round telling everyone what her and her partner will be called by the baby when it arrives (I'm 17 weeks just now). She hasn't discussed it with us which has annoyed me because I don't really want her partner to be called anything, he didn't bring up my husband, they got together when DH was an adult so isn't like a stepdad. We called my grans husband by his name as it was the same situation, I assumed we would just do this. I don't know if I'm just being hormonal and grumpy (feel free to tell me I am) but it's bothering me a lot that we haven't been consulted about it, I thought we would all decide together who was going to be called what. We're going to have to use these names for years.
How would it normally be decided?