Villain is 38/20 over 200+ hands. Very aggressive on the flop, but WTSD% is only 12. Line check please.

Party Poker No-Limit Hold'em, $ BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

Button ($49.70)
SB ($54.15)
BB ($50)
UTG ($5)
UTG+1 ($36.70)
MP1 ($42.30)
Hero ($51.40)
MP3 ($49.25)
CO ($57.75)

Preflop: Hero is MP2 with K, A. SB posts a blind of $0.25.
2 folds, MP1 raises to $3, Hero calls $3, 5 folds.

Flop: ($6.75) K, J, A (2 players)
MP1 bets $5, Hero raises to $15