[anfernee]

*grunch*
Any reads? This analysis might be flawed, and I may give too much credit to other players without any reads besides "TAG".
I'm assuming that you mean the SB is TAG. I don't know what your definition of TAG is but in my experience, TAGs that cap PF OOP will often have AQo dominated or crushed, or at the very least TT/JJ+. What of the BB? BB cold calls cap for 3b more(is he loose/tight? possible pp hoping for set? suited connector?). Don't forget that mp3 3 bet your pfr, so mp3 will likely be calling cap for 1b more.
You're now caught between the TAG SB that capped and the MP3 that 3 bet your pfr. I like AQo in certain situations, but in this situation, my WTF? radar is on high alert.

Flop: What hands could SB and MP3 have?? Would their PF hand ranges hit that flop? I'd check behind with the action you saw preflop due to the possibility that you may be C/R. SB did check to you...cap pf, check flop. TT/JJ? or slow playing QQ+? How has he played other big hands?
I think this flop bet is kind of thin. Is your bet for value? Everyone is getting 17:1+ and may be correct to call down with a lot of hands.

turn:
You now made two pair, but you may still be behind to QQ+/AK. However, due to passive flop play of SB/BB you may be ahead if they're pretty straightforward (players that bet when they hit, check when behind) players. I can also see TT and JJ in SB range with this passive post flop play. Some folks get too invested with these hands on boards like this esp. at uL. Again, reads help. If you're betting for value, I'm not sure if it's thin or +ev at this point as I don't have pstove handy.

River: what a [censored] river card.
There's a very good chance that your hand is no good. But the pot is big. As played, seems like a pretty standard call.

This is just my opinion/analysis. It is subject to interpretation and may be flawed.