WATCH: Nick Kyrgios Tells Stan Wawrinka ‘Kokkinakis Banged Your Girlfriend’

Australian tennis player Nick Kyrgios may have crossed the line with his trash talk on Wednesday during a match at the Rogers Cup in Montreal against Stan Wawrinka.

Kyrgios, a 20-year-old rising star who has had his maturity called into question in the past, met the veteran Wawrinka at the end of first set of their match. As Kyrgios approached the net, microphones picked up Kyrgios saying to Wawrinka, “Kokkinakis banged your girlfriend, sorry to tell you that, mate.”

Kyrgios is believed to have been referencing Wawrinka’s rumored girlfriend, 19-year-old Croatian tennis player Donna Vekic. Wawrinka, who divorced from his wife Ilham Vuilloud in April, has been linked to Vekic after she was seen in his box at matches.

Kokkinakis is Thanassi Kokkinakis, another young Australian tennis player who was previously rumored to be dating Vekic and has played mixed doubles with her. Kokkinakis has denied that they have ever been in a relationship.

Kyrgios had lost the first set prior to making the comment, and then bounced back to win the second set. Wawrinka retired in the third set with a back injury while trailing by four games. Kyrgios said in a post-match interview that the comment was spur of the moment. Watch that interview below:

Kokkinakis has not commented. Wawrinka responded on Twitter: