Time to tread cautiously?

[NYTyler]

Live $1/$2 NLHE at Tropicana in AC, Eight handed

Hero: $610
CO: $315

Preflop: Hero is in SB with 3 [img]/images/graemlins/diamond.gif[/img]3 [img]/images/graemlins/spade.gif[/img]
2 Calls, 2 Folds, CO Calls, BT Folds, <font color="red"> Hero Raises to $10 </font>, BB Folds, 1 Call, 1 Fold, 1 Call

Flop: ($32) A [img]/images/graemlins/spade.gif[/img]5 [img]/images/graemlins/diamond.gif[/img]3 [img]/images/graemlins/heart.gif[/img] <font color="blue"> (3 players) </font>
<font color="red"> Hero Bets $10 </font>, 1 Call, <font color="red"> CO Raises to $35 </font>, <font color="red"> Hero Raises to $150 </font>, 1 Fold, CO Calls $150

Turn: ($338) 8 [img]/images/graemlins/spade.gif[/img] <font color="blue"> (2 Players) </font>
<font color="red"> Hero? </font>

Now this guy is relatively new to the table but he said it was his birthday and I don't expect him to be much better than an average player at best. Keep shoving here? Because what am I beating here A5 or possibly A3? I feel like even though I have a set I may be topped here. Any justification here for slowing down with this hand after he called my monster raise?