Direct questions vs. assuming too much:
The couple here is testing the waters. In this case we imagine they both want sex.
Scenario 1: They avoid the obvious question, but they get drunk and they end up having sex.
They sober up. The girl thinks: Oops, I did it again. I feel so bad about myself. I shouldn't have drunk so much. He propably does not respect me now and thinks I'm a slut.
The guy thinks: Well that was easy. She must be sleeping around a lot. She must be comparing me to the other guys, she had. I don't dare to ask her, how much better they were.
They never see each other again.
Scenario 2: The guy promptly asks: "Do you ever have sex on the first date?" *smiles in non-threatening way*
Girl, a little surprised: "Well, to be quite honest, I have done so in the past. I guess it's not out of the question. I usually just need a few more beers to do that." *smiles back couragingly*
Guy: "Let's drink to that!"
They end up having sex.
Afterwards the guy: "That was great. Can we have another go sometimes?"
Girl: "Thank you for asking. Yes, why not. The other guys were just jerks, who used me when I was drunk. Never saw them again."
They agree on a second date.