Deleted Texts and Deleted Folder

I have a line with my ex partner, his plan is through a business line I have no access to. I want to know if he is able to view my text messages that have been deleted from my phone and deleted folder? It ended badly with him cheating and he is watching me like a Hawk since we have children and I feel my stuff is being monitored and I have no access to change anything because it’s a business line through law enforcement. I plan to get my own line soon but can’t at the moment….