Poor Oscar (time to start begging about needing another tank, lol), probably has no slime coat left.
I can understand if they would get annoyed, as it is there job, but they can still be polite about it. I was at Petland (or Abuse Land, as my friend calls it) at there was a HUGE male betta in the female betta tank. The famles were tiny! I told guy and this is what he said. 'That explains the empty bowl'. My mom knows I can, express, my feelings if I'm not in a good mood. I was so mad my LFS had fruit tetras I wanted to say something and she just told not to worry. I was ticked off a fair bit though