KQ. Two pair.

[toss]

Preflop is a fold to me against an unknown. You're hand is often dominated by an early position raise.

Flop you should raise for value. If villain 3-bets you should start fearing a better a hand. In this case I would calldown UI.

The way you played it I suspect villain has the same hand as you or AK maybe. A flopped straight seems unlikely since few people raise JTs from EP. KK and QQ are less likely since there only one combo of each. 88 and 99 deserves some consideration. I'd just calldown since there seems to be fewer hand we're ahead of.