What are the landlord’s right if tenant has a boyfriend living with her?

My tenant got a new boyfriend and he's been at the apartment every night except 1 for the last 6 weeks. She has a 1 year lease and we are just beginning. He goes there straight from work every day. He showers there, does his laundry there, eats there and sleeps there. He stores his motorcycle in the garage there along with his truck. You get the point. Anyway, I say he's living there. They do not. Obviously, the lease states only she can live there and she is a non-custodial parent so her boys will be there every other weekend. What can I do about this? She pays a flat rate for utilities every month however, they are all in my name. I set that amount based on one person. He is obviously using utilities and she is extremely careless. Can I put a lock on the thermostat? What recourse do I have? I don't want him there but if I have to, can I raise the rent and/or utility cost and require him to be apply and be put on the lease? Can I tell him he can't keep the bike on the property? There is only a one car garage and I don't want the property to look trashy. I also don't want to evict her but I must stop her from continuing to take advantage. She even got a dog and didn't pay the pet deposit. I told her she could have a dog but not a big one. She got a puppy that will grow to be 60ish pounds. A puppy who constantly barks and howls because she's stuck in a cage all day with no food or water, disturbing the neighbors, me. Yes, I am her neighbor. She's renting the mother in law's quarters of my home. It has a separate entrance and a shared washer and dryer. I don’t what to do and I want to write her a letter this week giving her what her options are.