What is the word for two or more people realise that something is happening but when no one will openly express it? A competition or problem, perhaps

I am writing about the competition we have with our friends on who looks the best on social media. I am trying to describe like an unidentified fight or competition with our peers. Like, no one is going to acknowledge that we are competing against each other but everyone knows deep down that it kinda is a competition.

The sentence is

• Even on days where I feel particularly confident with myself, I scroll on social media to see my classmates looking so beautiful and skinny in bikinis, no roll or stretch marks in sight, and I immediately feel defeated in the _____ fight for bodily supremacy.

Feel free to help alter this sentence in the best way. Just like an unacknowledged competition...?

EDIT: thanks guys for all your input!! very helpful!! <3

Solution 1:

"...and I immediately feel defeated in the undeclared competition for bodily supremacy."

• undeclared - not announced or openly acknowledged : not stated or decided in an official way : not declared, an undeclared war. (MW)

• "There was an undeclared competition among us."
• "I also remember an undeclared competition among the students."

Solution 2:

Tacit would suggest something unspoken but inferred or implied in the situation. Oxford English Dictionary, "tacit, adj.":

2. Not openly expressed or stated, but implied; understood, inferred.

That has the benefit of suggesting something both not openly expressed and understood or felt by the participants.

Even on days where I feel particularly confident with myself, I scroll on social media to see my classmates looking so beautiful and skinny in bikinis, no roll or stretch marks in sight, and I immediately feel defeated in the tacit fight for bodily supremacy.