When invitee user accepts the invitation, a connection between two users is created. This connection can be removed and two users will be excluded from each other’s network. To remove a connection, removeUserConnection mutation should be called. It has one required incoming parameter - userContextId which represents ID of the user context that is associated with the user who should be removed from the current API user’s network. 
  mutation removeUserConnection {
    removeUserConnection(userContextId: 1818) {
      response
      errors
    }
  }
If the mutation executed without any errors, a boolean value will be returned as a response indicating the execution status.
If the connection was removed, a new invitation can be sent again from one of those users to another.