[magmanus]

I agree with mackthefork: on 6th, he can see, that you have a 7, while it's obvious, that he only has an 8. So he was probably raising a draw and therefore he should have 2-3 in the hole, otherwise he can't be sure to draw to the nuts. So he has 11 outs (4x5 in his view, 4x6, 3x7) which is 1:3,36=29,7% to make his hand. As he invested 2 BB after your raise on 6th, he got 6.9:2, which is about the odds he needs, not counting implied odds. On 7th I also would prefer just calling, as you don't know, wether he hit his outs or not.
You could have reraised on 3rd street, which should keep him a little calmer on later streets.