Please let me know if I'm being petty. The background? My manager is calling a 3pm meeting today for everyone in the office, and afterwards, I'd like to meet with my staff to discuss an upcoming project.



My email: After our meeting today, would you mind sticking around, so I can go over an upcoming project? I won’t take more than 5-10 minutes of your time.


A co-worker's email response: Cool beans


My response: Cool beans?


His retort: I don’t mind sticking around after our meeting to go over the upcoming project.


I didn't respond. Am I crazy for wanting some semblance of professional email decorum? If we were talking and he said that, I wouldn't mind (although I've never used that expression, I don't judge guys who do). But on a work email? Come on dude...