I just spoke to DD and DS again. Here is what I know:
- Girls and I came upstairs at around 9:30pm to get some snacks. Nephew was coming out of the bathroom. I offered some to him and took it in to DS's room where I found DS in bed under the covers and the lights out. DS later told me that he did hear me come in and they then turned on the light and the tv, got themselves some drinks and picked at the popcorn.
- Vomit/hand soap thing and red marker on counter top happened sometime between when DH left for work at 10:30pm (he was on midnight shift) and 1:30am when I went to bed. This definitely was not the girls as I was with them the whole time.
- DS and nephew came downstairs sometime between 10:30-11:00pm to ask us to turn the movie down (DS's room is right above our family room in basement).
- DS said that after that, they went back to his room where DS fell back asleep and nephew played his Nintendo DS.
- About 30 minutes to an hour later, I heard motion upstairs and I remember thinking to myself that the boys must still be awake and expected to see them coming downstairs to watch the movie with us. They never did.
- Not long after that, at around 11:30pm, as I was downstairs with DD and her teenage cousins, still watching movies, we all heard the dog howling upstairs. We all looked at each other and wondered what was wrong with him. DD went upstairs, saw him waiting at the patio doors and just figuring he really needed out badly, let him out. She did not see anyone or notice anything else unusual.
- DD said that after I went to bed, her and her cousins watched a couple more hours of TV and then fell asleep. To the best of her knowledge, none of them went upstairs after I left to go to bed except for herself who got up in the morning to use the washroom (and to grab that bite of cheesecake).
- DS said he and nephew set his alarm clock so that they could wake up the girls in the morning. He said they ate some bagels and cream cheese for breakfast, played outside for a bit, played a prank on his oldest cousin (they put snow in her socks which DS admitted without hesitation was his idea).
- DS said he noticed the pistachios on the couch in the morning and mentioned it to nephew who said that it must have been the girls.
When I spoke with DD and DS, neither were nervous or had any inconsistencies in their story whatsoever. It could be that they are duping me (or that they are all of a sudden destructive sleepwalkers) but again, my gut tells me they are telling me the truth.
Personally, I still think nephew did it (as DH pointed out, he has a history of grand storytelling almost to the point of being a liar) and I think he did it after DS fell asleep and before I came upstairs, likely around the time I heard the motion and the dog started acting up. Whether or not he was sleepwalking while doing it, I guess will remain a mystery...?
Still no response from their mother to my email.