Maybe you shouldn't bother to check his phone. Because you knew you'd be stuck with him in a 3 hours long ride outside the city and now you found out about his chat with his ex

And all hell broke loose

After spending an hour of screaming and fighting with each other, now both of you just went silent on each other. He's behind the driver seat and you're in his passenger seat. No words, just the faint radio sound, both of you still waiting for each other to say something