OPP has built his stack by being extremely aggressive, he shoves AI on most flops/turns once a pot has been built. I havnt seen a player play back against him when he shoves so I havnt seen him show down anything. How should I play this FD on the flop? I assume turn is insta fold?

PokerStars No-Limit Hold'em, $0.10 BB (5 handed) Poker-Stars Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

Hero ($10.85)
MP ($5.50)
Button ($10.60)
SB ($10.05)
BB ($21.15)

Preflop: Hero is UTG with A, T.
Hero raises to $0.4, 3 folds, BB calls $0.30.

Flop: ($0.85) 3, 6, 6 (2 players)
BB bets $0.4, Hero raises to $1.4, BB raises to $2.4, Hero calls $1.

Turn: ($5.65) Q (2 players)
BB bets $18.35 (All-In), Hero folds.

Final Pot: $-12.70

Results in white below:
No showdown. BB wins $24.

FWIW, I caught him at it about 5 hands later after flopping top 2pair, raised him on the flop, he called then immediately shoved the turn which I called and took down the pot - he had nothing on the flop and picked up lowest FD possible on turn.