I have 400 hands on MP, where he played 24/13, 3bet of 5% and AF of 1.3. BB on 130 hands played 32/20 with AF of 1.4 and overall check/raise of 12.
I folded because i think that, even if is it possible that he has some draws, his action is very strong when he is check/raising OTT versus two players.
Do you think this is a mistake on the long run?

it´s a mistake in the long run to not bet that turn
oh and ur betsize on the flop is also a mistake .. in the long run

Bet more on flop - Like 2.4. We're getting called with worse overpairs on any sizing.

And bet big again on turn. I can't understand why you checked here?

I would bet bigger on the flop. Probably something like 2.25. On low and paired flops people will call you at least once with a pocket pair, so you want to make the first bet as big as you can.

On turn I would bet, because I want to get value from weaker hands. Checking to induce a bluff is not that good of a line because he is less likely to bluff because BB also called.

As played fold. MP bet into two opponents (which shows a lot of strength) and BB c/r him so i think that you're likely to be way behind here

bet the turn. as played, i would prob fold here too

Agree with other posters. You have to bet bigger on the flop. There are two other players, a flush draw, and a lot of overpairs that you beat but that will call a large bet. Then bet large again on the turn when the BB checks to you.

As played, folding is correct. But only against passive players like these (i.e., <1.5 AF), where you can't expect them both to be doing this action with less.

Against more aggressive players, once the UTG preflop raiser (you) checks the turn, the pot is there for the taking and they'll be getting it in very light here. Keep in mind that there's not much that beats you in their ranges. There are four combos of A4s and three combos each of 66 and 33. But there are six combos each of 55, 77, 88, 99, 10-10, and JJ...as well as a whole lot of club draws with overcards.

Also, be sure to make a note that the BB check-raised semi-bluffed with overcards and a flush draw on the turn into two live players. That's inconsistent with his AF stat and you'll want to know that in the future.

Bet bigger flop, and definitely bet turn. You've got at least one fish on the line. In the words of the immortal Denny Green "You let him off the hook!"

Ok guys. Thanks for your advices. I did not bet the turn because i think that when i'm opening UTG and i'm double barrelling a baby flop vs two opponents a decent player would fold any pocket pair here, probably also TT. So i checked because MP can bet a hand like 77 that he would fold to a second barrell. Do you think he would call if i bet again? Probably yes, considering how he played his hand but i didn't know this!
What size would you use OTT?