Would you allow your partner to go through your phone?

So, my bf and I have been on & off for 8 yrs , I’ve caught him twice now flirting with other girls while we been together , & we’ve been broken up for 4 months now, he’s been trying for the past 2 months to get back together, we’ve been having issues. I saw him tonight & I told him how I don’t like how he’s hostile over his phone. I would like to say I have NEVER gone through his phone but since he cheated on me 4 months ago which ended our relationship I feel insecure more than ever & i told him I don’t like how he’s protective over his phone , he told me that it’s his privacy and business and he’s always going to be like that , I told him that upsets me & I should be able to get on his phone , he told me I can get on his phone only if he’s next to me bc he wants to monitor what I do, he said I’m not allowed to go through his photos if I ever wanted to, it really upsets me bc before we broke up we talked about getting married later this yr & I asked him if we’re married he’d still be like that & he said yes, what really broke my heart is he said “ I rather end a 8 yr relationship than allow that to happen I draw the line here” & that really hurt me. I just want to know if I’m being dramatic . Do you guys allow your partner to get on your phone?

DISCLAIMERRR!!!!! I feel like some ppl are getting confused & assuming things. I found out he was cheating bc the girl he was flirting with messaged me on Instagram with screenshots !!! I never went through his phone to find out I said I have NEVER GONE THROUGH HIS PHONE, the only reason why I brought it up to him is because he doesn’t allow me to touch his phone & when i brought it up he said those things. Even if I got in his phone to look something up or watch a video he said he would feel uncomfortable & wouldn’t allow it . Thank you for everyone who is giving me advice an their pov.