envious
adj
~ (of sb/sth) full of envy; feeling, showing or expressing envy 满怀忌妒的; 表现出或表示忌妒或羡慕的
I'm so envious of you getting an extra day's holiday. 我真羡慕你得到一天额外的假期.
She cast envious glances at her sister's dress. 她以羡慕的目光看著姐姐的连衣裙.
He was envious of his brother's success. 他忌妒他哥哥的成功.
I suggest that we ask users of this machine what they think about it. We can photograph them using it too. Then we can put their comments at the top of the advertisement in big print. We can bring in some humour too. People enjoy reading humorous ads.