How did you find out you were dumped? Was it by text, in person, on the phone, or was it via the shrimp delivery guy that you sent to your girlfriend’s house? In this case, it’s bad enough that he decided the only way to apologize for a misdemeanor was to do it via the delivery guy.
To then find out that she was hanging with another dude, who then ate the delivery you paid for is a pretty bad night by anyone’s standards. It’s nice that he felt the need to thank the driver, he has manners at least.