In Lord Byron's "Don Juan," what was the lead character "half-smother'd" by?

Question

This would be the character's first adventure. Julia, a married woman, became his mistress. Her husband, Don Alfonso, was told that she was cheating on him and ran into the bedroom, accompanied by servants, in order to surprise her and her lover.

Anticipating this, Julia asked her maid to lie in bed with her, while Don Juan squeezed in between them and was hidden completely by the sheets.

Don Alfonso and the servants searched the entire room, looked under the bed, and failed to find Julia's lover. Julia, pretending to be insulted, shouted at her husband who, realizing he had been misled, hung his head in shame and left.

No sooner did the maid bolt the bedroom's door than Don Juan sprang from the bed "half-smother'd."

Now, pay attention:

He had been hid—I don’t pretend to say
How, nor can I indeed describe the where—
Young, slender, and pack’d easily, he lay,
No doubt, in little compass, round or square;
But pity him I neither must nor may
His suffocation by that pretty pair;
’Twere better, sure, to die so, than be shut
With maudlin Clarence in his Malmsey butt.

[...]    

Of his position I can give no notion:
’Tis written in the Hebrew Chronicle,
How the physicians, leaving pill and potion,
Prescribed, by way of blister, a young belle,
When old King David’s blood grew dull in motion,
And that the medicine answer’d very well;
Perhaps ’twas in a different way applied,
For David lived, but Juan nearly died.

Now: what exactly did he nearly die of?

Were they squashing him?

Or was it the smell?

Or just the lack of air?

What is Byron getting at here?

Answer 1

This is a joke, a double entendre.

die, v. I.6.e. 1600– intransitive. To experience sexual orgasm. Now somewhat archaic.

_{Oxford English Dictionary.}

In the plain reading of the stanzas, Juan “nearly died” because he was unable to breathe, but in the lewd reading, Juan nearly came because he was sexually excited by being squeezed between the two women.

Even in the plain reading, we have a choice about how to take “suffocation” and “nearly died”. Perhaps this is hyperbole, or perhaps his mouth and nose were indeed covered by pillows, bedding, or the bodies of Julia and Antonia, so that he was in danger of literal suffocation. Byron leaves this up to our imagination: “I don’t pretend to say how, nor can I indeed describe the where”.