But for Homme Sweet Homme, as it’s a pun on English Home Sweet Home, I think it’s logical to use Style/Language/English instead of Style/Language/French.
After all, the syntax of the title remains English, doesn’t it?
Personally I think title should follow the main language of the song so if we look at the lyrics:
"Mon homme sweet homme Il faudrait faire…)
“S’enroule avec mon mobile homme…”
They are song in a french with french words, only sweet is english but that s the only english word used.
Regarding “Aïe love you” it is english but in a middle of french lyrics and this expression “love you” could be seen as international now in a similar way than latin Title capitalizations for latin expressions in english
So i will tend to keep french capitalization for all three