Annoyed by this

My fiance got some early xmas gifts. And most of the envelopes have money in them. He was just opening a card and I just walked in the room, he took the money quickly and made a fist and showed me the card what was written on it and slowly left the room. He didn't tell me there was money or how much was in it.

I don't care about how much he's getting what really bothered me the act of it. Trying to hide it. I asked him about if the card had money he said yes but not how much. I confronted him that it annoyed me of him hiding something so innocent while I just walked in the room. He said, it didn't occurred to him he did anything intentional. Besides he wasn't keen on flaunting how much he got.

Would you be as bothered?

I let it go but I didn't like the "hiding" part.

Just to add.

Again, I don't care about the money. It's his money and he can do whatever. But since I was in the room he could have said "I got this card with money in it" it's the Hiding that bothers me. I just don't get why he feels the need to do that.