Ujian Peregangan Untuk Sweater

I'm going to wear a sweater in the office but I should choose the one that will hide my belly button when I raise my arms up. So I won't distract my boss. I decided to do stretch test. I try on 5 different sweaters and raise my arms up to check if u can still see my belly button. But even in the longest sweater of mine it looks like you can see my belly button. So I don't know what else I can wear and I decide to wear this one anyway