“I am with the parent who would not want the daughter to go out with a guy with such a minhag.”
That’s okay. I wouldn’t want to go out with her daughter either. But, frankly, I can’t imagine a date so bad that one would feel the need to blot out the memory of it, unless the date involved the police, thousands of dollars in damages, a wrecked car, Mexican drug runners, etc.
Having said that, however, there isn’t anything wrong with taking an occasional nightcap and you don’t even need an excuse for it.