[Shirley's a little too preoccupied with her thoughts to think about more than how she was supposed to have made that drink for Dirk and therefore he was supposed to drink it, and misses the part where he might be offering it to her for a reason. So instead she says:]
That was for you. I don't want it.
[It isn't meant dismissively, but the blunt tone doesn't preclude that possibility either.]
no subject
That was for you. I don't want it.
[It isn't meant dismissively, but the blunt tone doesn't preclude that possibility either.]