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 .
According to the above context, answer the following question.
What does the speaker mean by " half in the bag " ?


The person is already drunk .