YOU SAID:

I didn't want my girlfriend to make me a cup of tea as I still had some Fanta left

INTO JAPANESE

ファンタがまだ残っていたので、ガールフレンドにお茶を飲ませたくありませんでした

BACK INTO ENGLISH

I didn't want my girlfriend to drink tea because Fanta was still there

INTO JAPANESE

ファンタがまだそこにいたので、ガールフレンドにお茶を飲ませたくありませんでした

BACK INTO ENGLISH

I didn't want my girlfriend to drink tea because Fanta was still there