ingame i was thinking that i cause he;s a nit, he will not have suited connectors and i'm not sure if he will play like this with an ace. So i'm probably against a bigger flush (he had 17k behind after his raise and pot would be 32k if i had called)

If he was a nit then maybe his range is AA,KK,QQ,JJ,TT,AK-AJ Do you put KQ,QJ,JT suited in his range?

He could be doing this with a Set or TPTK with the King of diamonds. The Ace of diamonds blocks a lot of his flush range.

You got to call 5550 to win 27750 so we got to be good here at least 20% of the time to call which i think we smash.

If you call and the river is a diamond then I believe you can fold and still have a decent stack at 34,026.

Depending on the player too, if this is low stakes and you know hes a nit they potential get stuck to pretty cards such as a set of Aces.

I think its a call and then if no diamond or paired board then we call on the river.

Range of villain is JJ, AJ +. If you already have an A on the board, he probably did not have that FLUSH. Maybe set A or Flush QK.

Your fold is absurd without reads. He has at max 6-7 combos of flushes and you get a super good price. I would assume villain is clueless given his sizings and call and revaluate