I think I understand what you're trying to say silo ... i guess in your opinion the commercial should either commit to homosexuality openly (by having the father know of his son's sexuality) or not tackle the subject at all.
But we have to take the audience and McDonalds' corporate culture into consideration. They are by and large a very conservative company, not really the kind to push the envelope. In a sense this ad makes perfect sense for them for a European audience ... they portray themselves as not being afraid to broach the subject without actually saying "we accept homosexuality."
It is manipulative, cynical, and ethically weak from both sides of the coin really ... in fact more so if one were gay simply because (as you stated) it reinforces the dogma that homosexuality should remain hidden from one's loved ones.
But, if only for the fact that we're talking about it, it is effective from their POV ...
Ugh ... it's McDonalds, what do we really expect?
I don't know ... as a straight man having spent half my summers on Super Paradise Beach the whole conversation seems ridiculously outdated.
[edit on 2 Jun 2010 by schrodingers dog]
They do have a big job on their hands in almost ANY culture these days. Serving apple chunks and day-old salad just isn't going to cut it.
That's what freaked me for a bit. 
