Does his mom have any idea that he is smoking?
If they think he makes good decisions, it makes me wonder if they actually know about the decisions he is making. Maybe he acts more responsible around them, so they would be more inclined to think you just set some crazy rules. He's 16, it's generally safe to assume he has secrets from his parents. I don't even know how to handle that one, but if there is ever a good time or opening in conversation to mention it- I think whether they are aware of the cigars would be a question worth asking.
mistysue: You said exactly what I was thinking. How does OP know that this kid isn't lying to his parents AND to OP's son? His mom now thinks OP is the problem and may have NO idea what her son was pulling on this vacation. I hate confrontation too but what if his parents don't know he's smoking? Wouldn't you want to know about your child's behavior when he isn't around you? At 16 this boy may be starting secret behaviors that will damage his future.
OP, could it be that since you don't like confrontation he may have already pegged you as a pushover - sorry but it sounds like he had that figured out. I think it's VERY REVEALING that he behaved one way at your home for all these years and then suddenly, out of nowhere, on a trip AWAY from his family he pulls this behavior. And he HAS gotten away with it since you didn't give ANY details to his parents during this 10 day trip, nor after it. Being so vague with his mom has not helped anyone in this situation. She may have NO clue what went on. And he is counting on you not speaking up. The longer you keep your silence, the more he can bad mouth you since his mom is only hearing his "story" (ie: possible lies).
Also, did you wonder why your son didn't know his friend smoked cigars until this trip? Usually a teenager would have already bragged to his friends about his parents allowing him to do something forbidden. It makes it seem like he took them on this trip secretly.
Side note: Why aren't the fathers involved in this parenting issue? I would think your husband calling his father would get to the heart of the matter. Even if the boys know each other through school and the moms, I would still have my husband call his dad under those circumstances. Unless there are no fathers in both families. A 16 yr old boy may have his mom wrapped around his little finger, but maybe not his dad.
If you or DH had gotten on the phone to his parents during the trip and said: "Do you allow (johnny) to do this because that's what is going on right now and we certainly don't allow that" there may have been a completely different outcome to the trip.
At this point I would clear the air and just casually ask "So when did your son start smoking cigars? It was a real shock to us." Just her reaction to that one question will tell you whether she knows about this or is shocked to hear it. You could then continue: "You know, we really didn't appreciate him trying to influence our 12/13 year old to try smoking on our trip." She may be very embarrassed and/or defensive if she didn't know. She may also be rude to you if they DO allow this behavior and she's defensive of their lax parenting. She could overreact or avoid you. On the other hand, she may apologize and/or thank you for letting them know what their son was up to. She could react in any number of ways, but the bottom line is her reaction won't ruin your life... but speaking up MAY help that boy IF his parents are being fooled by him.
If you do speak up and find out his parents ARE permissive and allow this behavior (what are the odds?) at least you and your family will know for a fact what they allow and his family will truly know your objections. As it stands right now, the waters are very murky since you aren't speaking honestly with his parents. You may unintentionally be helping him hide prohibited behavior from his parents.
If you just can't see yourself speaking to her, would your husband consider speaking to the boys father and briefly explain exactly what happened? "I thought you should know what concerned us on this trip. I know if it was my child, I would appreciate knowing what my child's behavior was."
If they defend their son, fine. But at least they'll be doing it with eyes wide open.
I'm sorry this happened to you. It would really upset me too and would continue eating away at me - especially if I didn't deal with it. I would have had one of the adults (myself or DH) on the phone to his parents as soon as he started not only pulling these behaviors, but refusing to abide by your family rules. And ruining YOUR family trip.
OP, I hope I haven't hurt your feelings but that isn't being a saint as some have said (***see end of paragraph), it's allowing someone to walk all over you and your family and possibly allowing a child to fool his parents and maybe emboldened him to try other behaviors since he is (possibly) not getting caught. (***I won't get into a debate if PP'ers flame me, this will be my ONLY post on this thread, and hopefully it is of some help to the OP.)
Let's see, destruction of WDW property (pulling vases off the wall at resort), illegal smoking at age 16 (Penalties to Minors (it continually lists under the age of 18) quote: It is unlawful for minors to knowingly possess any tobacco product... FLA. STAT. ch. 569.11 (2001) unquote. Trying to get your 12/13 yr. old to smoke. And rude, disrespectful conduct toward you and your family. No, you were not being unreasonable. However, I would focus on his illegal behavior with his parents rather than his refusing to honor the texting agreement which they may think is no big deal. I would be thinking to myself more that I was proud my son saw what this boy is like, was embarrassed by his friends behavior and has limited his association with him until he (hopefully) improves and I would worry less about what he or his parents think of you.
At 16 this may be him beginning to see what he can get away with. So far, he is.
I hope you or your DH can speak up truthfully to those parents because in the end, it will be better than all this lack of communication. And it will help you have confidence in future situations in life that you can not only speak up for yourself and your family but enforce your family values when someone else is attempting to walk all over you.
I hope it works out well for you. Also, I'm glad you had some time after he left the trip to enjoy WDW with you family.
I'm so sorry you son had to learn about who his "friend" truly was that way. 
I usually sick my DH on someone. 
As a parent, I would want to know if my DS was being a pain in the rump. They may not care. 
Maybe you can write a letter? It might be easier to address that way. IF you want to address it at all. I can understand wanting to leave that one alone and moving on too. Tough call. I don't envy your postion. 
! Honestly? I would've sent him home with the lack of respect he gave and yes the extra charges for that would be his parents problem. The smoking would've probably have been the final straw and he would've crossed the line with me.... that's not even legal at his age! I applaud your son because of his right choices and it sounds like he has "his head on straight." So sad to hear the first portion of the trip was a drag but at least you didn't have him the whole time 
. I just couldn't take it anymore. So I'm really sorry, the good thing is you guys were able to salvage your vacation with your family and your son finally enjoyed himself!!!
