Pope Francis waves the faithful during his Sunday Angelus prayer in Saint Peter’s square. REUTERS/Giampiero Sposito

The possibility of Congress truly, massively embarrassing itself (is that possible?) and the entire country during Pope Francis’s historic address next week is starting to give some members the willies.

After all, we’re not talking about the president or some random foreign leader. This is His Holiness Pope Francis, whose official title is, among other things, “Bishop of Rome, Vicar of Jesus Christ, Successor of the Prince of the Apostles,” as well as head of state of the Vatican and leader of more than 1 billion adherents worldwide.

[A pope for all seasons]

So, for example, it might not do for the House Sergeant at Arms to bellow at the entrance something like: “Mr. Speaker. . . . The Pope!”

And it would be most unseemly if members who go at dawn to snag primo seats on  the aisle were to try to shake his hand or clap him on the back or, God forbid, hug him. (Maybe he should use a different entrance?)

It goes without saying no one will be boorish enough to say “you lie” if His Holiness mentions the environment or global warming — or if he reiterates doctrine on contraception.

But even the tradition of bipartisan, goofy, wild cheering, clapping or of standing O’s — or sitting boos — could be seen by many as way out of line.

Which is what has some people worried. So last week, four House members — Democrats Dan Lipinski (Ill.), Juan Vargas (Calif.), and Republicans Jeff Fortenberry (Neb.) and Tim Murphy (Pa.) sent a letter to House Speaker John Boehner and Democratic Leader Nancy  Pelosi, asking them to put out some sort of guidance “to the House and Senate on the appropriate decorum, protocol and behavior. . . .”

Members could use info on “how to greet the Pope, proper attire [no jeans?] . . . among other matters of etiquette,” the letter said.

“They should,” Lipinski told us, “applaud when he comes in and applaud when he finishes.”

We are hearing that Boehner and Pelosi are indeed now working on a “guidance card”  of some sort to members to, as the letter notes, ensure “proper respect for the Pope” and “avoiding anything that could be construed as politicizing or making a spectacle of his visit.”

Some members, such as Rep. Gerry Connolly (D-Va.), are optimistic. “The House and Senate will be on their best behavior,” he told the Loop. “There’s no upside in showing disrespect.”

One can only hope . . . and pray.