I personally fold unless further information on the villain, triple barrel frequency, notes etc.

If the V has value bet you on these sorts of boards previously/high aggression/triple barrel freq then I'd be more inclined to called.

I don't think it is exploitable to fold here at these limits as there tends to be more face up play, especially from 'regs'.

Thanks, I'm going to add triple barrel frequency to my hud :)

You're def right in saying that these regs to tend to play face up and his river bet is quite large when it seems obvious I'm not folding lol.

I advise you not to post the results of hands so you can get better evaluation. Personally, I fold this versus triple barrel unless he's real maniac.

with second nuts it's the top of my range and i have to call

I think the more interesting question is to be aware of the problems created by drawing to non-nutty hands on the flop in single-raised multiway pots. Actually, that's not a question, but here comes a ramble anyway:

We have position and quite a few outs, so once we get HU vs the raiser it can't be bad if we play well, but we only have 3 outs to the nuts. And he started with a tight preflop range and c-bet OOP into two opponents. What does this tell us about his flop range?

Those times we improve to the best hand and Villain goes limp, we feel successful. But that's not all that can happen. We are destined to pay off at least 1 street when we improve to a 2nd best flush/straight, while we won't have much implied odds when we make the best flush/straight (because Villain is OOP and will be wary of negative implied odds when draws hit).  Also, Villain will sometimes make us fold decent equity by barreling blank or pairing turns.

All of this is not to say you shouldn't peel the flop, because you have position, many outs, the c-bet isn't large, and the future looks slightly promising. What I am saying is that drawing to non-nut hands in multiway singleraised pots can be a significant leak, if are unable to fold after improving.

If this happens to you more than you think it should, the easiest cure is to fold and/or semibluffraise more of your weak peeling candidates on the flop. 

"drawing to non-nut hands in multiway singleraised pots can be a significant leak, if are unable to fold after improving"

Gold.

Multiway pots are a regular occurance in these games, weather they be limped or singled-raised. You see people losing big pots with amazingly bad hands and tbh my range in these pots at a full table is not wide in the slightest compared with everyone else so in many ways I feel I have the edge a vast majority of the time but really that can be a smoke screen and the leak you talk of. So I will be exceptionally mindful of that in the future. Thanks again bro :)