I don't like this calling 3 way pot, out of position in relation to two other opponents.
If only UTG raises, sometimes we can be calling with hands like AK, AQ, KK and AA to protect our calling range from multiple barrels, to play a heads-up pot, quite different from a 3-way pot.
Second, I don't like donking flop in this situations because although the caller sitting in the BTN has a capped range (it can only has some groups of hands, not others), the UTG raisor still has/possibily has AQ, AA, QQ and maybe 55.
We should be asking ourselves which hands we do call in situations like this that could go for a donks flop and we see only 55, A5 and perhaps AQ. As bluffs, we own the flush draws and some straight draws, but not enough to be leading here.
When UTG calls the donks flop it could have called with some pocket pair that should not be folding right now such as 22-KK, and the FDs and SDs mostly.
When UTG calls your donks flop it cappes its range for weak hands, such as underpairs in relation to the ace in the flop and the draws: hands such as AQ, AA and 55 should be raising your donks flop for protection because of the draws, so it is possible also, but more rare and we feel more confident that UTG doesn't have anything 'that good'.
OTT you should be jamming because there are only a couple of blinds left on your stack, making the fold on any possible river quite impossible. Even if you had more blinds left, you should not go for 1/2 pot (with hands that bet in this scenario OTT), but instead you should go for a larger sizing to put UTG all-in either OTT or OTR.
Weak players will see odds to chase draws everytime, so we must charge the ultimate price, specially OTT where our odds with TPTK, Two Pair and Sets are way much better compared to the flop. Well, you gave such a good price, plus a little blunder of betting so small OTT when you haven't enough blinds behind for the river.