sick on 是什么意思?Today, I bought a nice new dress for a work pa

sick on 是什么意思?
today, i bought a nice new dress for a work ***. but when i went in, a coworker hurried me into the bathroom saying, "don't worry we can fix this." she thought someone had been sick on me. thanks. that was just the pattern of the dress.
今天有个工作组的会,我穿了刚买来的漂亮衣服.我刚到办公室,一个同事神神叨叨地将我拽到洗手间,对我说：“别担心,我们会搞定的.”我估计他是认为谁sick on我了.好吧,谢谢他了——那只是我新衣服上的花纹而已.
这里的sick on是什么意思?