Question About Hand Etiquette

I was playing a 1/3 game where a player in seat one was picking up his cards off the table, maybe half the time revealing them to the player in seat 2. He may have been a beginner but he seemed to understand basics at least.

Anyway in one hand seat 1 and 2 were both in the pot and it became blatantly obvious every time he looked at his cards he was also revealing his cards to seat 2. I normally don’t say anything in these situations but since it was a bigger pot I asked the dealer if seat 2 can see seat 1’s cards. (I saw seat 2 look over multiple times at the other guy’s hand.) Some guy said “cmon buddy it’s not a big deal” but I feel that I lack information in a 3-way pot that player 2 now has. The dealer said nothing by the way.

Was I out of line or should the dealer be enforcing the protection of a player’s cards?