I agree. Sure they all took turns because nobody is going to sit there at an amusement park and watch someone's dog the whole time while they ride rides. Seems like he was invited to help watch the dog and although his actions are major jerk and very irresponsible seems like the kid has a horrible life. He was probably amazed and the fact he thinks he has to abandon a dog and literally run away from his loved ones because he's probably afraid he will never get an experience like this again is sad. Sucky situation all around for everyone.
Based on actions alone I'm going to say YTJ. When sil told you the girl name she had picked you should've mentioned you also already had that name picked. When sil got pregnant with a daughter and you knew she wanted the name YOU SHOULDVE TOLD HER. To her you guys had this conversation and she told you her name and then you both were pregnant with daughters then you had yours first and used the name she told you. That makes you the jerk. Of course you had this name picked for years but literally nobody can read your mind so what do you expect? It looks really bad. Should've just told her and if she reacted badly then she would've been the jerk.
By far NTJ. For one why is he going to work talking about he's upset he didn't get a watch? I'd definitely think something was going on. Seems like he knew she'd take the hint since she literally immediately went and bought him one. 500 dollars on a gift for a coworker isn't normal or appropriate at all. That's money you'd spend on a partner. I hope nothings up but this smells of infidelity.
Ntj. Absolutely ntj. I wet the bed until I was about 14. My bed wetting wpas caused by sexual trauma. My mom got me pull ups, had me not drink anything 2 hours before bed and even took me to the doctor for it as I reaches my teen years. When i stayed with friends she always made sure i had a pullup and told me to just secretly put it on so i wouldnt feel embarrassed (kids are mean). Eventually it became rare and then completely stopped. One time my dad dated a girl when I was around 5 or 6 and I wet the bed. His gf was furious and they made me scrub the bed with soap and water. I felt absolutely ashamed and embarrassed and I still remember clearly being forced to clean it basically as a punishment for something I couldn't control. I get your nephew is 13 and old enough to wash his bedding but his parents, your SIL AND brother, need to get him medical attention asap. He doesn't need to feel ashamed or afraid to go stay with family or friends because he wets the bed. And he 100 percent should be allowed to wear a pull up. (Definitely not a diaper sil is sick acting like he's being a "baby" for something he cannot control)