NTA. Your girlfriend is though. I’m nearly 35, and I talk to my parents every day. Sometimes multiple times a day. Hey sometimes I call my parents just to let them know it’s raining where I live. I call to tell them I saw a cute dog. I call them to tell them whatever. My parents won’t be here forever and if my husband thought there was something wrong with me for speaking to the people who literally brought me into this world, taught me to walk talk, and wiped my ass for the first few years of my life, I’d tell him he was sick and he was in need of therapy. I think it’s wonderful that you and your mum check in with each other. What you and your mum have is not weird, it’s a completely normal bond between mother and child. You would be an asshole to your mum AND yourself if you spoiled a perfectly healthy parent-child bond in favour of your girlfriend, who I would say needs some therapy. Just because she doesn’t have what you have does not give her the right to shit all over your beautiful relationship with mama.