"酒肉朋友"英语怎么说？

每个人身边都有很多朋友，其中一些只是在一起吃喝玩乐的朋友，这种朋友往往忠诚度不高。大家称这种朋友为“酒肉朋友”。
fair-weather friend：
字面意思看来，fair weather是“好天气”的意思，就是说，这类朋友只能在天气好，情况好的时候才能和你在一起。
To see the explaination from native speakers: a friend who is only nice to you when it's convenient; someone who's wishy-washy; someone who is a "backstabber" ;someone who abandons you in certain situations.

Example：
Every time you're with Bob, you won't hang out with me. You're such a fair-weather friend.