What should I do? 🤷‍♀️

I posted earlier (I am fuming) and I've calmed down a lot now but can't sleep.

Long story short some disgustingly desperate girl who works with my boyfriend sent him messages after a night out begging for him to fuck her and even send him nudes. Thing is he teasingly played along saying no but flirting and in the end sent her a dick pic. All while I was waiting for him to come to bed.

We are too deep into the relationship (4 years and living together) for me to just leave him or throw him out over this. And I believe in second chances since he has never done this before.

So I'm looking for some suggestions of how I could deal with this? Like what is acceptable and what is too far? For example asking him to delete or block her? Asking him to delete snapchat (because he never actually uses it until this dick pic)?

I am still fuming at this girl and pretty annoyed at him for letting it escalate but I've never been in a situation like this before. I can't think straight but despite planning to stay with him I still think there needs to be some sort of consequence for him?