Preflop
Standard open although at 2NL I dont see any point in going this small. People are calling stations at these stakes, so just go bigger for value. At minimum 3BB.
Flop
He lead into two players for half pot, and I just dont think, you have a lot of fold
equity in this spot, so I prefer to just call. The issue with raising is also, that you build up the pot, which is not so great, when you are drawing to the very obvious second nuts.
Turn
You made your hand, but its a little optimistic to try and get 2 streets of value. So I might actually check back here for a bit of deception and also pot control. Make it look like you were raising top pair "for protection", and now you slow down, because you did not like the fourth spade coming.
You did bet however, and now he check-jam. This is a vomit spot, and you put yourself into it by raising on the flop. I do actually think, you can fold here. He only need 1 card to beat you, so its not that difficult to have. There are basically 45 ways to have it, which is quite a lot.
And I just dont see him taking this line without the A of spades. 4-flush boards are very special, because its so easy to have the nuts, and you can not block the nuts without having it. So what are people even turning into a
bluff here? Maybe some world class players are balanced and actually have some bluffs, and some complete donkeys do this with Qs or Js. But everyone in between always have As, when they make this move.
Conclusion
The key thing here is, that you lose to 45 combos. So this is not the same as having KK on AK952 4-tone, where KK is second nuts, and you only lose to 3 combos of AA. Its not how many different
hands beat you, its how many different combos. So you basically overvalued your hand, and this started already with the raise on the flop.