Am I over exaggerating??? Bf n other girl

This random girl messaged me with messages between her and my bf, I got mad at my bf cause he was carrying on the convo and she sent me that he liked her pics am I wrong for getting mad at him he said he was doing nothing wrong and I told him he could have just said thank you that’s it..

Ps she sent me a pic of her asking what he was doing and he told her laying down wby? Like why is he continue the convo with this girl???

‘My bf is the white message