A guy is in a meeting at a restaurant or bar that has alcohol. He gets some spilled on him and when he gets home his girl smells it and kicks him out thinking he’d been drinking. He returns to the bar/restaurant a couple times and has a waitress called DD. Pretty sure it’s even on her name tag. He sees her leaving after her shifts with different men and assumes she’s a hooker. But it turns out DD stands for designated driver. He apologizes for his assumption and I think ends up falling for her. It’s been over 10 years since I watched it probably but I can’t remember anything else and Google hasn’t been any help.