YOU SAID:
Jack jammed jelly into his jeans and found out he was jealous of his friends thing
INTO JAPANESE
ジャックは彼のジーンズにゼリーを詰め込み、彼が彼の友人の事に嫉妬していることを発見した
BACK INTO ENGLISH
Jack stuffed his jeans with jelly and discovered that he was jealous of his friend
INTO JAPANESE
ジャックは彼のジーンズにゼリーを詰め、彼が彼の友人に嫉妬していることを発見した
BACK INTO ENGLISH
Jack stuffed his jeans with jelly and discovered that he was jealous of his friend
That didn't even make that much sense in English.