The recently axed pro dancer alleges he walked in the couple in a changing room during last year's series.
But Brendan claims what he saw suggested otherwise.
"One evening I went in the boys’ changing room, walked in the door and there were AJ and Molly," he said.
Brendan claimed to The Sun newspaper: “I wouldn’t have thought anything of it if they had gone, ‘Hey, Brendan, nice to see you’. But when I walked in the door, they went, ‘Sorry, sorry! Didn’t see you there’.
“Two young single people who get together on the show — it’s great, right?”
New Zealand born Brendan announced that the BBC had decided not to renew his contract.
"They've made an editorial decision not to have me back on the show," he said. "I'm in shock. I got a phone call. I've had 15 incredible series."
Brendan admitted: "I'm disappointed. I've always known this day would come. I'm a very strong character, some don't like that.
"I've never been contracted for more than one year. I still wanted to be part of it. My passion is still very much there."
Strictly Come Dancing 2018 will air on BBC One in the autumn.