As far as I know, “whiskey dick” refers to not being able to get it up, losing your erection, or having a partial erection due to drunkenness.

To your original question, alcohol/drunkenness will often make a guy last longer. I think this is a relatively well known phenomenon.

One reason is desensitization: alcohol tends to numb sensations. This leads to needing harder oand/or longer stimulation to get off.

Another reason is mental state: alcohol tends to help people let go of inhibitions and nerves. Guys (really, people in general) can get anxious about their performance. Worry about cumming too fast is often self fulfilling; the anxiety and focus on the problem makes it happen. Alcohol usually lowers anxiety, keeping that vicious cycle at bay. It’s the same with erection issues. Alcohol can quell anxiety and make it easier to get it up… but it’s also walking a tightrope; too much alcohol and whiskey dick may occur.

Edit: oops, I’m not a lady. Just a dude who has experienced of all these things :p