Is he being rude or am I overreacting?

It's probably bothering you because that wasn't the response you were expecting. The rest of the email seemed nice...but why would he put you on hold for his friends. Perhaps he is abiding by the rule, Bros before Hos. But he should totally respect your feelings...maybe you can tell him it bothered you a little bit and you can ask him why he couldn't multitask his friends and you?! Good luck sweetie!