Weird curiosity

I have come to my cousin sister’s place, I am 23M and she is 32. She is a senior software engineer at an MNC. Yesterday she wore a stretchable black deep scoop neck top along with a small gold chain to office. When she came back and sat down when I noticed a folded paper slip inside her bra and that made me really hard. I wasn’t expecting that from her as I know this is usually done by aunties and a few years back when my aunt(her mom) kept her mobile phone inside her top, she was completely against it. I was very curious to know what that slip was and wanted to mock her hypocrisy but was scared to ask or tell anything about it. Should I ask her about it? If yes, then how should I do that?