AQ 3-bet pf in position

[Fryguy]

Opp is 25/10/1.8 and has been pretty aggressive with his hands. Because I 3-bet preflop and he donked into me, I felt obligated to raise the flop and represent a big pair. When he just called and donked the turn, I was somewhat confused but I thought A-high might be good here a reasonable amount of the time, and pairing either of my cards might be good. Because his postflop play has been decent, I also thought there might be a chance he was just bluffing and tried to donk to look strong, as I've got a very tight table image at this point.

Party Poker 0.50/1 Hold'em (10 handed) converter

Preflop: Hero is MP3 with A[img]/images/graemlins/diamond.gif[/img], Q[img]/images/graemlins/club.gif[/img].
<font color="#666666">3 folds</font>, <font color="#CC3333">MP1 raises</font>, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero 3-bets</font>, <font color="#666666">4 folds</font>, MP1 calls.

Flop: (7.50 SB) 5[img]/images/graemlins/heart.gif[/img], T[img]/images/graemlins/heart.gif[/img], 4[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">MP1 bets</font>, <font color="#CC3333">Hero raises</font>, MP1 calls.

Turn: (5.75 BB) T[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">MP1 bets</font>, Hero calls.

River: (7.75 BB) 4[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
MP1 checks, Hero checks.

Final Pot: 7.75 BB