A married man having a gay affair is not an uncommon subject in the gay themed cinema for its titillating shock value. 'Isaac' could be still in that category, but it deals it in more subtle and mature manner.
The best point is that it gives just as much focus to the wives. A wife character in gay affair dramas can often portrayed as a simplified victim or even a villain. Women in 'Isaac' are much more multi-dimensional and frankly more charming than their husbands.
Where this film lacks the most is the portrayal of the guys' past. A lot of issues and emotional entanglement of Nacho (and to certain extent, of Denis) comes from the unresolved past, their intimate teenage friendship. I mean the title is the name of their 3rd friend for a reason.
But the sequences from their past are too fragmented, too caricature-like, and too shallow comparing to the present sequences that it affects the believability of the present situation negatively, especially why Nacho should become so taken by Denis.
I enjoyed it and could recommend it... but it could have been better.
