River 3♦ (3-flush): Hero checks, BTN jams 88bb into 50bb

Multi-way River | 3-way: CO | 100bb effective | Difficulty: Expert

Players in hand: Hero (CO), BTN, BB

Hero hand

A♥K♣

Board

A♣K♠4♦8♦3♦

Action so far:
PF: 3-way, Hero opened AK from CO
Flop A♣K♠4♦: Hero c-bets, BTN calls
Turn 8♦: Hero barrels, BTN calls
River 3♦ (3-flush): Hero checks, BTN jams 88bb into 50bb

Pot: 50bb   To call: 88bb

Villain range: BTN flat-flat-jam line: AdXd, KdXd, QdJd, JdTd flushes, sets 88/44/33 (boat), AdKd nut flush. Bluffs: rare 5d6d turned worthless

Your move: