YOU SAID:
my dog and cat had a party last night, but they didn't invite me
INTO JAPANESE
私の犬と猫は昨夜パーティーをしましたが、彼らは私を招待しませんでした
BACK INTO ENGLISH
My dog and cat had a party last night but they didn't invite me
INTO JAPANESE
私の犬と猫は昨夜パーティーをしましたが、彼らは私を招待しませんでした
BACK INTO ENGLISH
My dog and cat had a party last night but they didn't invite me
That didn't even make that much sense in English.