This is correct. The Novus Ordo is a sacrilege and a mortal sin, whether said on a Sunday, a Saturday afternoon, or at a wedding, or at a funeral. It is wrong to go to it no matter the reason, as it is a sin against the Divinity directly. It is worse than an abortion (and would we sit in to view an abortion?) Where is our faith? We are required to love God first - "He that loveth father or mother more than me, is not worthy of me; and he that loveth son or daughter more than me, is not worthy of me." (Mt. 10:37).
And in case anyone should recoil from having to choose God over relatives, sometimes a hard thing indeed when it comes to funerals and weddings and nasty family reactions, Our Lord immediately says:
"And he that taketh not up his cross, and followeth me, is not worthy of me." (Mt. 10:38)
With all due respect to Fr. Wathen, Dimond brothers, et. al., I'll take my Catholic doctrine from Pope St. Pius X and Pope Benedict XV
§ 2. Passive or merely material presence can be tolerated for the sake of honour or civil office, for grave reason approved by the Bishop in case of doubt, at the funerals, weddings, and similar solemnities of non-Catholics, provided danger of perversion and scandal is absent.
While I understand the perspective that the NO may be considered a sacrilege worse than any protestant service and also that one could argue that neither Pope envisaged the NO when promulgating the code, the plain fact is that they DID promulgate the code with the given wording. So that's what we have to work with.
The Popes didn't
command Catholics to attend non-Catholic services.
They did not
recommend attending them.
But they
did tolerate it.
What that means in practice is that a reasonably sane, stable-in-their-Faith Catholic can choose to attend cousin Fred's NO funeral. He can also choose to
not attend.
Those that have some kind of scruples over the matter should
not attend.
Everyone is entitled to their opinion but this situation is difficult enough, do we really need more self-appointed high-priests of the trad-sanhedrin convicting everyone of mortal sin over debatable points?