Contact his wife and asks if he she wants his pics back since he clearly sent them to the wrong wife. 
And don’t listen to the people telling you your wife cheated. I read your replies and no, she didn’t. She’s just went the passive way which is completely understandable. But it’s time to maybe sit her down and tell her she needs to be more proactive in putting a stop to this nonsense and she doesn’t need to reply, blocking works fine and as a married woman she sort of owes you that much respect. If that makes sense?