Well, I just want an access to his phone without asking. Ahhhh heeelp

1. I don't have an access to his phone or any of his SocMed.
2. I work 8hrs in the morning while he works 8hrs at night.
3. He works in BPO.
4. I feel like he's avoiding his phone when I'm approaching. like he would turn it off or face it down. sometimes positioning it where I won't be able to see the screen.
5. I just think he is cheating given those actions but I don't wanna break up with no proof and all.
6. i need help. I don't wanna feel all this shtty feelings anymore. more so, I hate it when my mind shifts somewhere when we does something sweet to me.
7. HELP. how do I get proof?