strict parent

How to let my mom let me stay over by my boyfriend. Sigh.. I am 22 years old and my mother is strict with me I am not sure if she trust me or not but I give her no reason to no trust me because I don't go no where. My boyfriend wants me to sleep over by him but idk how to convince my mom to left me in a respectful way. I know I am not a child anymore but gosh..