Is it wrong or is it okay

I trust my partner but like i lend him my phone all the time yes i hav nothing to hide from him and well whenever i ask him for his phone to use he always says no his phone is locked and well not even do i know his password and we sometimes argue about that because before we both had each others passwords for everythimg he use to let me his phone but after he made a new account on fb he didnt gave the passwrd to me but as of now he doesnt have one and he has changed phone and no he does not let me his phome for nothing k get mad at him we have 4 years and 6 months dating and 1 year and 9 months engaged