Thomas told The Sun he thinks he is "being shunned" by Megan and her new in-laws because he "made a profit on the staged pictures". "I see it in her eyes, I see it in her face and I see it in her smile", the 73-year-old said.
Mum-of-three Catherine, also 36, attends the tennis championships every year as she is the royal patron of the All England Lawn Tennis and Croquet Club, after inheriting the role from the Queen in 2016.
"I don't care whether she is p***** off at me or not". I don't like the one I'm seeing now.
Thomas said it looks like his daughter flashes a "pained" smile.
Whether it's just her "having a couple of bad days", or a more permanent state, Markle is nonetheless "worried".
"It really worries me". Prior to the royal wedding, Meghan was responsible for buying her own clothes for appearances and reportedly spent nearly $30,000 of her own money on clothing for royal events through March 2017.
"There's a high price to pay to be married to that family", he said.
Thomas Markle sees 'fear in Meghan's eyes' as Royal Family 'piles on pressure'
Maybe then, he and Meghan can patch things up.
He also blasted the seemingly outdated outfits Meghan now wears, despite her gaining praise for her royal fashion savvy.
From the perspective of all the envious doe-eyed young women watching Megan enter the royal family, it's hard to believe that any woman in her position would feel anything close to "terrified" or "miserable", as Thomas Markle asserts.
But, the same can't be said for Meghan Markle and her dad. I don't get it. "I'm not blaming Harry or anyone else but they are following rules that don't make sense to me".
Mr Markle said he is sorry for "anything that went wrong" and is keen to put any differences he and Meghan have to one side.
Mr Markle, who had a heart attack six years ago, did not attend the Royal Wedding after being hospitalised for chest pains on the day he was supposed to fly to the UK. "I have had a fairly successful life. I miss you very much".