[Kwantum]

Call. On heart turn if you're led into I think it's an easy fold given UTG's description, otherwise check behind. On a blank turn, if bet into I probably keep calling down, UTG can easily be betting worse, otherwise I make a hefty bet if checked to and evaluate from there.

It's unlikely he flopped a flush and I think you still can get some value from his other hands like AQ/AJ/KK/QQ/JJ with a heart in his hand.

Also, you're severely under-repped here. I like calling the flop, not putting in a raise. Control the pot, you maximize when he's semibluffing worse that he normally might check/fold on a less drawy board, and you minimize losses when he happened to flop a set, flush, or is freerolling with Ah Kh.

Cliff notes: call flop