I'm 19F. I'm dating this guy from past 3 years and I love him so much but he won't let me use snapchat

I'm dating this guy from past 3 years and I love him so much . I never used snapchat but now that I'm graduating and my whole friend circle is on snapchat, I too wanna use it . But he's giving me permission to use snapchat cause he thinks that snapchat is for cheaters so I gave him my id and password. I don't have male friends and h doesn't have female friends and honestly I don't seek a male friendship as I love him so much. But he said if I use snapchat that'll make him feel disrespected in this relationship. I assure him that I won't add any male to my account but he's not listening. He said people in a relationship shouldn't use snapchat.