It was kind of interesting , and everyone seemed really nice . By the time I had gotten there , he was half in the bag . It was really funny to see him so hyper , as he was drinking and excited cause the ex had gone and there was no real drama that night . So he was a little tipsy , and starts running around hanging out with everybody , and at one point keeps trying to get me to sit on his lap .

Question: What does the speaker mean by " half in the bag " ?
Answer: None of the above choices .The person was being friendly .The person had just gotten out of a relationship .The person is already drunk .