actually, you can and should often raise this flop.
Reason being, at LLSNL, if there is a flush draw on the board, villains will almost always put you on the flush draw and call way wider than they normally would.
Also, if any V has the FD, he is never folding.
So basically, in spots like this TPTK on a FD board, I'm a big fan of raising. Obviously, wish we were last to act so we could really put the screws to our villains with perfect raise sizing with the bloated pot. But as is, I don't mind a raise and in fact I think raising flop is optimal and sets us up for a turn shove if we are called by 2 villains.
There are too many hands that have too much equity when we flat. Come turn, about 1/2 the deck sucks for us if we are 3 or 4 way, but heads up our hand will have a decent amount of equity on the turn.
To be clear, flatting isn't terrible by any stretch. But I like a raise to $40. FD's are never folding and all 9x and underpairs "can" call because they will put us on a FD. Now, the interesting question is if we can/should raise/fold or raise/call???
Again, thinking about typical LLSNL psychology, most LLSNL players don't shove flop with their sets and 2p hands in this spot. Most LLSNL villains want to wait to peel a safe turn THEN they shove. So a decent percentage of 3-bet shoves over the top of our flop raise will be FDs imo. Obviously villain dependant, I mean, if the OMC shoves over the top of us on flop then yeah, odds are we are beat. But if the typical aggro shoves us on flop, I'm fine calling for under 100bb in this spot.
Basically, if we think about why we raise, it's to get better hands to fold and lessor hands to call. In this spot, a ton of lessor hands can call. Obviously we get owned by 2p and sets, but with the FD out there, the combo of lessor hands that can call goes way way up. So I like a raise on this flop.
Or put another way, I love raising in situations where villains will soul read me for an incorrect hand and put me on "a flush draw" and just click buttons and call me down so they can be awesome