betting small otr to try and make a tight passive player who rarely makes aggressive move make a bluff is a bit stupid. bet bigger each street and call river as played imo. if he's not a tard he's not raise calling worse surely

and also you can bet the turn and then check back the river which means youve still got good value, rather than checking the turn and then poss checking back on the K river. b/folding vs passive fish is usually always a good line and imo is > than checking ott

if youre just going to get 1 street of value you have more chance to get it on the turn rather than on the river as bet check bet line is usually a hand
if he's a fish and calls the turn, he'll prob convince himself to call otr after investing so much, and you might have like A9o or something right