18 bets on the river?!

[Jon1000]

6-12 LHE Lucky Chances

I can't remember the preflop action perfectly. I apologize. It was full ring. I was in the BB w/ 6h 4h and MP+1 made it two bets to go. everyone calls of course, as do I, and it is 6 to the flop which comes . . .

3s 5s Kh
Checks to UTG who bets. MP+1 two bets. SB calls. I call. Four way now.

Turn: 10h. SB bets out. I raise. UTG calls. MP+1 three bets. SB folds. I call. UTG folds. Heads up now.

River 7c. I bet out. He raises me. This goes on 18 times. He asked if we could just put it in, but the dealer said no. You have to go bet by bet "b/c that is procedure". We got to eighteen and he had like only 70ish left behind before he just flat called me w/ top set.

I am a no limit player and only play 9-18 and 6-12 while I wait for a seat. Usually very conservatively. Is 18 betting w/ the second nuts normal live? What a douche.