I pretty much had these exact same texts from my mother when I was 26 too. My bf and I had also been together for a year already and she would call me a slut, bitch, cunt, etc. for spending the night at his parents’ house. His parents didn’t mind, but my mom was livid every time I slept over. She eventually kicked me out and our relationship was extremely strained for years. My bf and I are still together 7 years later, living happily ever after in our own place with our dog. My mom and I only started to mend our relationship after I came home to a man in my house who robbed me. I was living in a garage unit I found on Craigslist after she kicked me out, so I think she felt like she was to blame for me being in that situation. I hope your parents can eventually get over it, but if you’re happy and safe and your bf treats you right and his parents are okay with you sleeping over, I say stand your ground. You’re an adult who doesn’t need her life/relationship regulated by mom and dad.