Marianne what I have heard is that it has been presented to people, and some still do follow this line of thinking, that there are primarily two states of life - two vocations - people can be called to - the married life, or the religious life. In the past there has not been much acceptance of a "vocation" to the single life.
While I have heard about some priests erring by having an adult heterosexual affair, I have not heard about it on the level we are hearing about the homosexual crisis.
And, again, I wonder if it is not a case for the Church to look at allowing our priests to marry again? Eastern Orthodox priests are REQUIRED to be married before being assigned to a parish. The only Orthodox priests that do not marry are those who enter the monastic life. We allow our Eastern Rite Catholic priests to marry. It is not a definitive doctrine of the Church that our priests cannot marry. It just seems to me, given what we have seen in the Church around the world with the abuse scandals that it might be a prudent thing for the Church to take a look at again.
We cannot assume that a homosexual priest would present any problems at all. It would be unfair to assume that a homosexual priest or any other homosexual Catholic is practicing their inclination.
In this respect, I see nothing wrong with a break from the Catholic tradition of vocational choices. A homosexual could commit to neither vocation, marriage or an order, and remain a single Catholic lay person. I think to enter into either knowing that there is an insufficient calling, is untruthful to self, and to others.
I am unsure regarding the church's view on homosexual male-female companionship marriages.