Mandatory dashes in lyrics

[Lukas-Fabian Moser]

Folks, especially those of French tongue,

how should one deal with a word like "entends-tu" in Lyrics?

{
  c'8 8 8
}
\addlyrics {
  En -- tends-tu
}

If I am not mistaken, the dash (is it one?) between "tends" and "tu" is 
mandatory, and it should probably be centered between those to 
syllables. This makes it tempting to just to do

{
  c'8 8 8
}
\addlyrics {
  En -- tends -- tu
}

but the LyricHyphen between those two words isn't printed if the 
syllables are close.

None of the solutions "tends- tu" and "tends -tu" seem right, either.

What would be the "right" way both semantically and visually?

Lukas