But a 19-year-old is a teenager. By definition. Their age ends in "teen." Your comments are jumping through hoops to justify how creepy it is to pressure, coerce, and ply a young adult with alcohol to have sex. Using "young adult" vs "teenager" doesn't change how gross the premise is.

When I was 19, I was literally dating a 32-year-old. I thought I was mature enough to make those choices. I regret them all the time, because looking back at 19-year-old me, I know that I was still developing. Our brains aren't full developed until 25. I'm not saying people 18-25 shouldn't have sex. I'm saying that when a person 10+ years out of that life stage start predating on young people, there's a huge power imbalance that makes consent a nuanced issue.