Button seems laggy over a small sample size. SB is new at the table.

I check the flop to induce/get action from weaker pocket pairs on the flop/turn and because I am either way ahead or way behind and the turn card will change nothing about that.

$0.25/$0.5 No Limit Holdem
5 players
Converted at

Stacks:
UTG ($50.00)
CO ($55.02)
BTN ($43.48)
SB ($50.25)
Hero ($132.14)

Pre-flop: ($0.75, 5 players) Hero is BB [Ac]
2 folds, BTN raises to $1.5, SB calls $1.25, Hero raises to $5, BTN calls $3.5, SB calls $3.5

Flop: [8h][Ks] ($15, 3 players)
SB checks, Hero checks, BTN goes all-in $38.48, SB calls $38.48, Hero folds.

Raise more preflop.

I think this is a pretty straightforward fold.

if there was ever a spot to check/fold AA its here