Reduce your risk at the wrist. Wristbands for legal drinking age party goers and designated tap tenders greatly reduce your liability as a party-thrower as well as reduce your likelihood of being in violation of certain liquor laws. One for the road can easily lead to an officer as a chaser. Designated drivers keep delightful parties from ending in disaster in the highway or holocaust in the holding cell. The Oxford Police have no more desire to visit your party than you desire for them to be there.
Prior planning prevents poor parties.
If the officer has a search warrant. If the officer has your consent. These rules also apply to cases where the police ask to look inside your bookbag. If they don't have a search warrant you have the right to say no. At the same never attempt to physically prevent an officer from doing his job.