Not remotely trying to defend the DH here.. more 'this might not be the disaster and catastrophic life changing thing you fear'...
Maybe 'Golfing in Portugal' has always actually been 'golfing at various courses around portugal and spain, depending who is going, who is driving, where's good, what the weather is like'..
Maybe the OP has been told that and not listened because frankly, who would its golf.. BORING.. or maybe he's never divulged the yawnsome details of golfing and choosing the course because she's not interested (again, who would be, blah, golf, its just an excuse to do fuck all of any use all day long).
I went to a conference in Belgium, I spent a good portion of that weekend in France - my OH had no clue whatsoever how we got there, nor where we were staying because of the few details I told him, he didn't really listen, as the salient points were 'Widdlin isn't here all weekend, she's out of the country, she might fetch back treats'.
When I go to conferences in the UK he rarely has an idea which end of the country I've gone to never mind which city!
The point being, it may not occur to him there is any reason to tell the OP exactly where he is!
Or, he is in fact shagging his way round Spain with some woman he has been hiding for the last 10 years, his golfing mates are in on it and he's a shit of the highest order.
Currently there isn't solid evidence of anything at all!