O’Sullivan triumphed in a dramatic night at The Crucible, as a second semi-final climaxed in a final-frame decider.
It was The Rocket who prevailed after rattling off three frames in a row but Selby expressed his unhappiness with some of the shots made by O’Sullivan, who smacked the cue ball on occasions – most notably when trying to hit a pink nestled behind the black.
'An absolutely ridiculous shot' - Ronnie O'Sullivan smashes cue ball
“I just felt like it was obviously a bit disrespectful to me and the game,” Selby told Eurosport.
“Obviously if you are playing anybody else, there’s not many players who will get down and just hit them 100 miles per hour when you put them in a snooker.
“Sometimes they will try and work it out, try and play safe or try and get you in trouble back but I just felt he was doing that throughout the match really.
Mark Selby on Ronnie O'Sullivan: 'I felt it was disrespectful to me and the game'
“So I just thought it was a little disrespectful to me and the game, but you’ll have to ask Ronnie about himself.”
O'Sullivan had earlier explained his behaviour.
"If I'm snookered, I'm going to smash them all over the gaff," he said on Eurosport. "The rule is so bad, it's there to be abused.
"You know if there's an advantage in him missing it. In certain shots, there isn't...It's just painful having the ref put it all back. I haven't got time for that, man!"
'If I'm snookered, I'm going to smash them' - Ronnie explains controversial moment