OK, so this gentleman had been acting like a pretty straightforward donkey by the time this hand was played: Folded to c-bets a lot, donked his TPGK on a 3-to-a-straight flop, then minbet late streets when the 4-th card to a straight hit the turn. He was also only limping preflop.
After he'd raised me I put him on a 7 and decided I wanted my chips in there, so I 2-xed trying to induce a shove. Given the action before it seems he's afraid of nothing in this spot, but I really don't like flatting here: I'm out of position, and any attempt to control the pot is doomed, since it is too big already and checking the turn is likely to induce further bluff. And, IMO, it is too weak to give him credit automatically: Reads can't be solid after just a few hands...
I wonder what the best line is. Any help is appreciated.

It's fine.

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