@Emily1491 I believe you have a pretty clear assessment of what happened. The guest was being nosy, or perhaps was even checking around to see if there was anything worth stealing (this actually seems like a stronger possibility to me than just nosiness and I doubt he intended to assault you in your bed).
And people can do strange things when they're stoned from morning til night. When my daughter was 17, she lived on an island and had to walk past another guy's cabin through the bush to get to her little cabin. They became friends and would often share a bottle of wine or a coffee and some conversation.
Now this guy was in his 50's. She certainly didn't give him any indication that they were anything more than friends. She was an innocent teenager who was open and trusting.
One day when she had come back for the weekend to my place, she said, "Mom, read this" and handed me a letter she had gotten from him. He went on for 8 pages about how she was the woman he'd been looking for all his life, how they were soul mates, and should be together, yadda yadda.
This happened to several teenage girls on that island, with various men old enough to be their father. These guys would sit in their cabins, stoned all the time, fantasizing about the beautiful young women they knew and became divorced from reality. People referred to them as "bushed".