Hi Opt,
With your sibs visiting, your H is definately stressing out and is once again over sensitized about the bad parts of what happened to M. During your sib's stay, I would drop bringing up any talk about the office. It would be too easy for him to associate you bring up the subject as piling more on him right now. Focus on making him feel more comfortable in what he deems unfriendly territory. A swim in the pool was a good start, keep to safe topic for chit chat ... maybe even intitiate some water games. You want him to think that even tho sibs are there, he still enjoy the time he's there too.

'til later,
KAW