I'm looking for an idiom or expression that could be used for criticizing someone who tries to hide a big event in their life/ an important issue but that event would be inevitably disclosed or obvious sooner or later.

For example:

1- A pregnant woman who tries to hide her pregnancy

2- A celebrity who has had a nose job or another cosmetic surgery but tries to keep it as a secret

3- A person who has engaged or married recently but tries to not disclose it

4- A country that sells military equipment an ammunition to another country secretly ( but after those equipment are applied or used, everybody would find out where they have been made in.)

We Iraninans use this idiom:

"You can not ride a camel furtively!"

Is there any idiom, expression, or proverb for criticizing such actions or behaviors?

PS:
I found this cartoon by googling that Persian idiom, it is about the Yemen's president (Abd Rabbuh Mansur Hadi) but I couldn't find more explanations (, so I changed the Persian texts into English).