I have the similar thoughts about that as I have about heterosexual teachers. Teachers set examples for children and should not openly expose their sins. Theology teachers in Catholic school should believe and try their best to live the Catholic Church teachings on *all *matters.
A Catholic teacher with homosexual tendencies but who understands and believes the Church teachings and who lives a chaste life (key point!) is better than an openly defiant heterosexual. Any teacher who openly defies Church teachings should not be entrusted with teaching in Catholic schools. I hold this opinion for any subject, but think it even more important for theology teachers.