Found nudes on his phone

My boyfriend and I had broken up 2 weeks ago to try and fix things for our daughter so far everything is going good

He’s away for a couple of months for work and last night I logged into is messenger I wasn’t looking for anything I just clicked bc it was registered on my phone

There was 3 conversations where he has send the same picture of a girl naked .

It was no porn picture it was an actual picture from a camera

Idk if someone sent it to him or he took it like cheated

He send the phone to 3 of his guy friends

What should I do ?