Fishy play or unconsciously correct? Hero is honestly unsure...

Played this hand in my last session. Made a number of decisions without really thinking about them too long or hard, and so in retrospect I'm not sure if they were anywhere near optimal.

1/3. $500 max. 9 handed. Friday, around 5pm.

V1 / UTG - mid-late 50's WG. Been at the table a few hours. Never seen him here before, but my sense is he sort of knows what he's doing. Bit of a TAG-fish - tight agressive, but fairly face-up in most pots. Can't remember him 3B'ing much if at all, and definitely don't remember him 4B'ing. Started around $650.

V2 / CO - late 50's / early 60's WG. Hero and V2 know each other well. V2's been crushing it lately, in tournaments and cash, at 1/3 and 2/5, possibly even 10/10. Former professor of psychology (not kidding), likes to use speech-play and get inside opponents' heads, and SUPER aggro. Capable of 3B'ing very light and jamming with just a draw or total air. Lots of meta-game / leveling with hero. Currently getting obliterated, stuck around $2k on the session, starting the hand around $550.

Hero / BTN - early 50's WG. Currently having an unbelievable session. Crushing the regs. Destroying the fish. I am the poker gods chosen son today, up over $1700 in just a few hours. They are giving me good starting hands, sending me whatever I need, and generously blessing all my reads. Starting around $2200.

OTTH...

V1 opens UTG to $15. Standard open size for the table, though we'd seen some EP opens up to $20.

V2 3B to $55 from the CO. A little large for a LP 3B, but possibly due to V2 wanting hero out of the hand.

Hero on the BTN looks down at KQdd.

Ordinarily, I might fold KQs facing an EP open from a tight player and a 3B from anyone who isn't V2. If V2 or any other reg opened from MP/LP, this would be a mandatory 3B. In this spot, folding felt too nitty, and 4B'ing felt too spewy, so without thinking about it too much, I opted to just flat call, even though cold-calling a 3B isn't really a thing, according to pros.

So...I dunno - flat call here with KQs too fishy, or okay?

Blinds fold, V1 calls, and we're three to the flop...

FLOP ($165 net of rake) - QQ9tt. I'm not 100% sure of the suits. No diamonds, obviously.

Action checks to hero. At this point, I'm not sure if I should bet or check it back, and what size I should take if I do bet. I have no idea what I'd do if I bet and get raised by V1, but I'm not crazy about giving my opponents a free card on such a wet board. So, without thinking too long, I casually toss out $75 using three green chips.

Here again, I dunno - should I just check? Is this 45% pot size stupid? Should I go 1/3 or less, 2/3 or bigger?

V1 rage-mucks. V2 thinks for a few seconds, mutters something that didn't quite register with hero's brain, then jams for roughly $500.

Before everyone says this an obvious insta-call, I hesitated in-game, thinking about previous hands where I'd seen V2 say something weak-sounding before jamming, the meta-game, and the recent table dynamics.

While this sort of weak-statement speech-play is usually an indicator of the nuts within the general population, I've seen V2 do it with both value and bluffs against other opponents. Against me, though, he usually had thick value. The only exception I could remember was an earlier hand from this same session, when I 3B him pre with A5s, and he 4B-jammed with KQ, of all hands.

V2 can obviously show up with 99 or AQ for value, and he's capable of 3B'ing pre and jamming with QJs or a decent draw. But I wasn't sure if my bet sizing might have induced him to jam lighter, or if I was running so well and my bet looked so strong that he'd never jam without AQ or 99. He's already stuck four buy-ins. I figured he'd have to tighten up at some point.

Like, from his perspective, what hands am I cold-calling pre that bet almost 1/2 pot on this flop? Do I somehow have some random low-equity bluff here? The only obvious bluff I could see would be JTs with a FD or BD flush draw, but if he's jamming as a bluff, I'd expect him to have that, not block it. Likewise, JJ and TT block me from having JTs. And I didn't think he'd over-play AA/KK this way, when my 3B-calling range pre could have 99 or QX in it.

I'm guessing no one here is ever folding KQ in my spot.