I don't feel that I am a terrible snob. Really.. would you guys let your children go to someone's home where the parents are smoking in the same room!? I wouldn't not have tolerated it back WHEN I smoked and I certainly don't feel like I should tolerate it now just to spare the poor woman's feelings. If she gets offended when I tell her that I don't want my child in a "smoking" home then she'll just have to get offended. I didn't do it and I don't want anyone else to do it either. I can and will be nice about it.
I wouldn't like it and I never have/will smoke in front of children. I just don't think a couple of hours once a week in a smokey room is going to have much effect on a healthy 13 yr old. It's not about the woman's feelings... it's about the kids. They'll talk, the other boy will feel embarrassed, maybe your son will too. Kids pick up on these things and saying something will give off a "my mom thinks she's better than your mom" vibe. IMO it's best to avoid anything confrontational and to just encourage them to hang out at your house, or to play outside at his. Or drive them to the movies or the mall. There are oodles of better solutions that save face for everyone.