I'm a sleever as you know - 11 weeks post op now and I haven't had any nausea, reflux or vomitting since leaving hospital. As well as being lucky, I think I've helped myself by following all the rules religously.
I started back on solid food at the 4 week post op stage and can now eat almost anything but pasta and bread (toast is ok) but I eat in teeny, tiny portions and that attracts a whole lot of attention when eating in other peoples company.
I explained to the kids with scant details that I was having an op and why (to help me lose weight and get healthier) and that their Dad would be looking after me for a couple of days and Granny would be staying to have an adventure with them. My kids visited me in hospital once the main tube was out and I was careful to look as good as possible (bit of slap and a false smile!) and get up and go for a walk with them etc to reassure them I was fine.
My six year old (youngest) now sometimes forgets the situation and loudly points out that I'm not eating much. A gentle reminder of why and she is good as gold again. She did find the two weeks during which my mother in law stayed to help hard going and missed Mummy's ways of doing everything but she was fine once she went home again and that's a dim and distant memory now.
They now ove the the fact that I'm now nearly 5st down and willing to go swimming / bike riding etc etc and see the whole experience as very positive. I have always been honest with my kids in that I have a problem with food, teaching them to stop eating when full and to eat healthily most of the time with occasional treats as its not good for your body to be overweight.
Regarding telling other people. I would say that at 9 weeks out and living in close proximity / eating together, it will be impossible to conceal! Youw ill have to choose high protein foods and avoid all high fat, high sugar foods. I eat in tiny portions which to be honest, must seem ridiculous if you haven't had WLS / know I've had WLS. I'm absolutely no comfortable with fibbing.....they always come back and bite you on the bum surely??? and besides, what on earth would you say to explain away that!? I have told all my close friends and all of my family in order to avoid awkwardness. Everyone has been amazingly supportive (barring my husbands older brother) who is a health freak, vegan, cycling mad weirdo to be honest so his opinion is about as important to me as the cats! lol Even he hasn't been out and out unsupportive but his tight lipped demeanour says it all for him!
Re excersize, I was told to walk, walk and walk some more to build up stamina etc immediately post op and was cleared for proper excersize at my 6 week follow up. I am now cycling, swimming and gyming (although a mean old personal trainer all but killed me last week!) Most online info seems to say 6 weeks too.
Sorry to have gone on but hope I've been helpful. Jo x