expression requests - Is there any Idiom or provide verb that would imply " You cannot conceal such facts or issues"?

I'm looking for an idiom or expression that could be used for criticizing someone who tries to hide a big fact in their life/ an important issue while the nature of that fact/ issue is so that it will be disclosed inevitably.

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 fallen in love with somebody, engaged or married recently but tries to not disclose it

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

We Iranians use this proverb:

"You cannot ride a camel furtively."

Like in:

"Why are you trying to hide you're pregnancy?! You'll eventually start showing and people will know. As the proverb says "You cannot ride a camel furtively".

Is there any idiom, expression, or proverb for criticizing behavior or implying " such facts or issues cannot be concealed"?

PS:

1- For a person who tries to conceal the fact he/ she is in love with somebody, I just found this proverb: "Love and cough cannot be hid", but I don't think it can be used for my other examples too.

2- In the bellow cartoon the former president of Yemen is shown while riding a camel furtively (I found it in a Persian website and it had no comment, so I just used it for showing that Persian proverb and translated the Persian texts into English).

Answer

If, like the Americans mentioned in this good ELU answer, you don’t mind slightly mixing two metaphors/expressions (the ones about the elephant in the room and the 800-pound gorilla) and then using the result as a simile that, although unrelated to the strict meaning of either of the two originals, would nevertheless mean "such facts or issues cannot be concealed," you could consider:

[That’s] like trying to hide an 800-pound gorilla.

(from ‘Labor of Love: The Story of One Man's Extraordinary Pregnancy’ by Thomas Beatie, via ‘Google Books’ where it’s used in “Hiding a pregnant man is like trying to hide an eight-hundred-pound gorilla.”)

cf:

Elephant in the Room

Usage
The term refers to a question, problem, solution, or controversial issue which is obvious to everyone who knows about the situation, but which is deliberately ignored because to do otherwise would cause great embarrassment, or trigger arguments or is simply taboo.
The idiom can imply a value judgment that the issue ought to be discussed openly, or it can simply be an acknowledgment that the issue is there and not going to go away by itself.

"800-pound gorilla" is an American English expression for a person or organization so powerful that it can act without regard to the rights of others or the law.
The phrase is rooted in a joke riddle:
"Where does an 800-lb. gorilla sit?"
The answer: "Anywhere it wants to."
This highlights the disparity of power between the "800-lb. gorilla" and everything else.
The term can describe a powerful geopolitical and military force, or, in business, a powerful corporate entity that has such a large majority percentage of whatever market they compete within that they can use that strength to crush would-be competitors.
(The metaphor includes an inherent bit of hyperbole; the highest weight yet recorded for an actual obese gorilla is 600 lb. (270 kg). The average weight is 400 lb.)
The metaphor has been mixed, on occasion, with the metaphor of the elephant in the room.

(both from ‘Wikipedia’)