*in on something
1. involved with something, such as an organization or an idea; informed about special plans. (*Typically: be ~; come ~; get ~; let someone ~.) There is a party upstairs, and I want to get in on it. I want to get in on your club's activities. Mary and Jane know a secret, but they won't let me in on it.
2. receiving a share of something. (*Typically: be ~; Come ~; get ~; let someone ~.) I want to get in on the new European business that is supposed to develop. We will all want to get in on the scheme.