River 2♥ (paired): MP bets 22bb into 36bb

Multi-way River | 4-way: CO | 100bb effective | Difficulty: Expert

Players in hand: UTG, MP, Hero (CO), BTN

Hero hand

J♣J♦

Board

8♠6♠4♣2♦2♥

Action so far:
PF: 3-way to flop, Hero 3-bet JJ
Flop 8♠6♠4♣: Hero c-bets, MP calls
Turn 2♦: checks through
River 2♥ (paired): MP bets 22bb into 36bb

Pot: 36bb   To call: 22bb

Villain range: MP flat 3-bet, flat flop, check turn, bet river line: medium pairs 99/77/55 that improved to two pair on the second 2, busted Ts9s/9s7s, A-high give-ups. Some 22 slowplays exist but rare given preflop flat range

Your move: