Getting annoyed in my relationship

I'm starting to get really annoyed in my relationship.. we are ALWAYS nearly every night at my partners mums house. We never ever do anything together Anymore.. it's always with her mum and sister. Even when I say lets go for breaky JUS US for once she tells them and then they want to come then we have to wait for them to get ready..

Every single weekend we are there just sitting at her mums with her sister and her baby. No matter how many times I tell my partner I want to do something together jus us.. We still end up at her mums after.

I'm just getting very annoyed...

She wanted me to cancel my day Saturday with work cause she had Saturday off.. and im thinking why.. so we can go sit at her mums all day. So i went to work and she went to her mums all day.

She can never just sit at OUR HOUSE and chill.. it's always gotta be at her mums.. so latley i haven't been going to her mums.. She went today after we went shop and I stayed home.. by myself.. Like always when i don't wanna go every night.

On Thursday I said let's go for dinner saturday night or see a movie or something and she said " oh we cant I already told my sister we will come over as mums going out " so we sat there all night.. and did nothing.. I am starting to hate my weekends off I rather be working.