What do I do about the rude company that I invited to stay at my house?

I told my 18 year old brother that he could stay at my house while his girlfriend is visiting from out of town. He didn’t want to stay with our mom since she is very strict, and won’t let them sleep in the same bed. I have a nice house with a pool, and they have their own space during the day since my husband is out of town, and I am at work all day. I don’t even know his girlfriend, but figured we would visit once she got to the house last night. Within 10 minutes of being home from the airport, the two of them are in the back room going at it, and I have the t.v. up in the living room and can still hear what’s going on! Then, they decide to take their “party” to my only bathroom and they are in there for 45 minutes with the water running. This morning at 5 a.m. I am woken to them making all kinds of noise in the next room, when they both know I get up early for work!! I also noticed that half of my prescription pills were gone from my makeup bag this morning. (which were well hidden in my bathroom cabinet) In addition, my brother who normally talks to me while I am home, has barely said two words to me. His girlfriend won’t even hardly respond when I try to speak to her. I am so angry, but I don’t even know where to begin!! Should I just kick them out?