Maundy Thursday was not a seder

The Last Supper/First Mass had only men in attendance - The Apostles. What happened in that upper room was not a seder although it has been popularly described as such.

http://www.jewishencyclopedia.com/articles/13376-seder

Seder, is nowhere to be found in the Gospels. Rather, renowned Jewish Scholars, like, Baruch Bosker ("Origins of the Seder") observe that the Seder (Order) traditions (according to Rabbinical literature) bring us only back as far as 70 A.D. the time after the destruction of Jerusalem and there is no evidence in Rabbinical literature of a Seder prior to that.

As for Christian Catholics, the idea The Last Super was a seder (Scott Hahn), well,  that claim runs afoul of Sacred Tradition as, to just cite a few sources, the exegesis complied about the Institution of the Eucharist in, Catena Aurea, teaches us; "But how is our Lord said to sit down, whereas the Jews eat the Passover standing?"

But even more conclusive is this; "Council of Trent (Sess. 22, c. 1): “After Christ had celebrated the ancient Passover, which the multitude of the sons of Israel sacrificed in memory of their going out of Egypt, He instituted a new Passover, that He Himself should be immolated by the Church (ab ecclesia), by means of (per) the priests, under (sub) visible signs, in memory of His passage from this world to the Father, when He redeemed us by the shedding of His Blood, and delivered us from the power of darkness, and translated us to His Kingdom.”

Here is the exegesis of Cornelius a Lapide:

"And supper being over, when Satan had put it into the heart of Judas, the son of Simon the Iscariot, to betray Him. After the legal supper and the common supper too, before the Sacred Supper—the institution of the Eucharist—Christ washed the feet of His disciples; for by this washing He wished to show with how great purity and humility we ought to approach the Eucharist. Observe that Christ partook of a triple supper with His disciples, the ceremonial, the ordinary supper, and the Supper of the Eucharist. In families of ample means, the lamb being insufficient to satisfy the hunger of so many persons, there usually followed the ordinary supper, at which they ate other kinds of meat. And so Christ washed the feet of the Apostles after the two former suppers and before the third. And hence it is clear this washing of feet was not merely the ordinary usage of the Jews according to which they were accustomed to wash the feet of their guests, but a sacramental ablution, by which Christ was preparing His disciples for the reception of the Eucharist, converting the ordinary usage into a sacred ceremony. So that they are in error who gather from this passage that Christ washed the feet of His disciples after the Eucharistic Supper and before the lengthy discourse which He then made them, and which is subjoined by John. Of this number is S. Cyprian, or whoever is the author of the “Treatise on the Washing of Feet.” “The Lord,” he says, “had now distributed to the Apostles the Sacrament of His Body; Judas had now gone out; when, rising from the table, He girt Himself with a towel, and at the knees of Peter the Lord Himself, on bended knee, about to wash the feet of His servant, discharged towards him an office of consummate humility.”

Ecumenism is the Universal Solvent of Tradition and the Judaising has got to stop