did you meant, why is it that the parents reject homosexual relationship? Or that the couple commited suicide?
For the first question... all I can say is that, this is how the society educated them in the past, that's why they had the mentality of rejecting homosexual relationships. However, I do believe that 'our' generation should be more open about these issues. Also, I strongly believe that if 'mom and dad' could relax and being provided with enough information about gay life, gay relationship... i~ i really hope they could loose up...
as in on the suicide... i have no clue... perhaps, because those who finally understand the consequences of suicide are... in heaven... (?)
(sorry, they last part was meant to be a joke... )