Is this normal behavior for a niece?

I started dating a 55 yr old man who told me he loved me on our second date which I found strange. He has an 18 yr old v pretty neice who attends college in a near by city. She stays with him on occasion at his house and they visit her home in WI.
He told me that his niece got scared one day alone at his house and told him she thought his house was odd or strange things happening like doors opened that were closed, etc. anyway she slept in his bed with him and he said she make a wall between the two of them with pillows....I think this is very sick behavior...He usually sleeps nude but told me he had on pj's and I think this is the first time she has slept in the same bed with him.then when they visited her parents in WI, she told him she saw a scary movie and might have to sleep with him again...SHE HAS A SISTER AND PARENTS that she could have bunked with or slept on the floor...SHE DID NOT SLEEP WITH HIM BUT THE FACT THAT IT WAS EVEN BROUGHT UP IS CREEPY TO ME.
I let it go the first time but I told him this time that I felt he was crossing a line....he said it was innocent and that is why he told me about it..
WHAT DO YA'll think??????