Perhaps you need to re-think that. The kiss, as it were, was a homosexual assaulting a sleeping heterosexual.
There was no gay agenda at play.
It showed an evil, lying, scheming homosexual (ever see THOSE on TV?) imposing himself on an unsuspecting heterosexual male.
The story continued with how the situation was to be handled and how the House would deal with this evil, lying, scheming (ever see THAT on TV) homosexual, and how this assault ruined and destroyed the homosexual.
That scene was far, far from advancing a homosexual agenda. Quite the opposite.
Please watch the series from the start to get a true understanding of the characters involved.
Go here and see for yourself: You tube link "Downton Abbey Gay Kiss"
In the first or second episode of Season 1, there is a willing kiss between Thomas and a male visitor to Downton Abbey. Then, there isn’t another one, I don’t believe, until later in Season 3 (Episode 5 or 6?) when Thomas comes on to the footman, both of whom have been set up by Ms. O’Brien’s treachery.