Drunk girls like attention.
he's exactly right. it is young girls that are drunk often times like attention from the boys and know that the boys like it when they touch each other or kiss each other. the reason being is that the boys aren't as brave to be the ones to fondle or kiss the girls and so they let the girls do it.
it's a phase that usually happens in college, but high school girls are catching on too. it's all about the attention, whether drunk or not.
Definitely NOT a good idea to mention it to the parents. Kids will be kids, and kids will rebel further if reprimanded for their actions.