You play a sound opening style with Flannery (hence the 2♣ bid). 4♠ was 1430 ask for ♥, and 5♠ confirmed all the keycards and asked for specific kings, with 6♥ showing none.
So, pass or 6NT?
If it matters to you, this is the 20th of 24 boards in your session and you feel very confident that you have a 60%+ game going.
Plus... it's free!