Chances are, they will be gone soon. 20-year olds make lousy tenants because their lives are in such flux that they seldom stay long in their first rental. Plus, they typically know nothing about the legalities of renting and make many mistakes regarding damages, nuisances, and the joint and several liability they have just signed on to, etc. Which also means the homeowner is not too smart to have rented to them and will soon have bigger regrets than you.
Meantime, be reasonably friendly with them, tell them you are experienced and well-acquainted with landlord-tenant laws, and would be happy to answer any questions they might have on the subject. You can then tilt the answers in your favor when any problems arise. It is only a matter of time.
