If BB/UTG are kinda bad I like a flat to keep worse hands in the pot since you have position, sick equity against one + two pair hands and crush any other draws. Getting a bad player to start putting in money could be worth more to you than re-raising someone who just potted this flop into 3 other players.

That said, it might be difficult to get action on a 3rd spade with the in hand.

The way you played the hand is fine, but flatting might be better depending on the opponents and game texture.