Can I ask her about him?

Well my Mom went on vacation and when she came back she brought a guy. I've never seen this guy before. All she said was "This is John". He moved in. John is a little creepy and disgusting and he like takes PDA too far with my Mom. So I woke up this morning and my Mom was gone and John was drinking Orange Juice and wearing only boxers. He's like "Hey Sunshine your Mom went out". So I've been in my room all day with the door locked. I don't know who John is, where he came from, why he's here...heck I don't even know his last name. I know my Mom is an adult and all and she can do what she wants but is it okay for me to start complaining now?