Traduko - Nederlanda-Greka - zoetje ik hou van je! ik wil u nooit meer...

The other two "you" is informal,singular?

CC: Martijn

Correct
They're all singular

Γλύκα σ'αγαπώ!
Δεν θέλω να σε χάσω ποτέ πια!
Είσαι τα πάντα μου!

Lein, since you're on-line could you tell me
if this phrase is formal "ik wil u nooit meer kwijt!"=you plural and the others use you singular informal?

CC: Lein

Since this requester is Flemish, I think all this is in singular, informal language.
Urunghai, do you agree?

CC: Urunghai

Yup, even though the requester uses "u", it's informal.
I tend to use "u" often when talking to friends myself.

By the way, I've just seen Martijn's bridge, which is correct of course, but 'again' is used like 'from now on' - it doesn't necessarily mean they have lost each other before. Another way of saying this would just be 'I don't ever want to lose you'.

Ah yes, of course. Lein is correct.

Νομίζω ότι η ενναλακτική του Aspiebrain "δεν θέλω να σε χάσω ποτέ πια" μας καλύπτει και στις δυο περιπτώσεις (είτε εννοεί δεν θέλω να σε ξαναχάσω, σε περίπτωση που τον έχει χάσει ήδη μια φορά, είτε εννοεί γενικά δεν θέλω να σε χάσω τώρα που σε βρήκα)

Τhank you all!!

CC: Urunghai AspieBrain sofibu

awww! Thank you for the kiss! I am blushing now... ;-P