Hang out with him without the posse. Instead of being seen as someone who’s just part of the gang, go and do something alone with him. Whether it’s grabbing lunch or working out together, the time you spend alone together can help you or him determine if the two of you have chemistry together. Also being alone allows him to see a more intimate side. Plus he may be interested in you but is too shy to act out on his actions when all of your friends are around.