Ramblings of an itinerant rocket scientist...

Try not to write off the friends... Usually it is just circumstances that keep you separated on weekend evenings. It is not a function of whether they desire your company at a given time, but more often the other factors that dictate your inclusion. Are you keeping the kids, are they keeping theirs, do they have out of town visitors, etc. It is counterproductive to view these situations as a deliberate exclusion. You may be beating yourself up for no reason, and I suspect the stress from preparing for Spain is taking its toll. The friends likely realize you are making preparations, and are trying not to interfere.