SB playing 21/14 over 250 hands, fairly passive post flop. pre - pretty standard flat. flop I decided to raise UTG cbet as he was playing pretty solid and wanted value from big PP, what do you guys think here? flat possibly? Anyway the SB calls which was interesting, I put him on pp 4s 5s A2s 78s, turn I decided to X back and evaluate river, then he leads pretty big, it just felt like he had it as mentioned above he was very passive post flop... the more I think about it the more im thinking I prob shudda called as he doesnt have many 78 combos and probably most likely set of 4s / 5s, 22 I think he folds to my raise. Keen to know your thoughts, im pretty sure if its run through PIO probably a call :(

ps - pocket 77, 88 99 even TT is possible, but I think he checks river here alot with these holdings