UFC lightweight contender Dustin Poirier says he is “living rent free” in rival Conor McGregor’s head following their recent Twitter spat.

Poirier defeated McGregor via first-round TKO at UFC 264 in July for his second straight win over his rival. While his second-round TKO win at UFC 257 earlier this year was a clean stoppage with no controversy, the trilogy fight saw McGregor break his leg, which led to the doctor stoppage. Even though Poirier is 2-1 all-time in their series and McGregor is out for the next year with his injury, it hasn’t stopped the Irishman from taking to his social media as of late to take shots at Poirier and his family. But Poirier says he doesn’t care.

Speaking to ESPN‘s Laura Sanko, Poirier said that McGregor is living rent-free in his head.

“It doesn’t really bother me, I don’t really care. When I think about in hindsight, like today, I was thinking about it like, ‘The guy’s probably losing his mind.’ He can’t really train. He’s got a hurt leg that he’s trying to rehab. Rent free. I’m just living rent free,” Poirier said (via MMAFighting.com).

Although Poirier is next in line for a title shot against UFC lightweight champion Charles Oliveira, he has spoken openly about moving up to welterweight and fighting bigger guys.

“Of course I would,” Poirier said. “Those are some big guys, man. We’ll see. I definitely can fight at 170. Honestly, now at 155, my metabolism has caught up. When I was cutting to 145, between fights I would get a lot heavier than I do now. I think my body was getting messed up and holding on to a lot of weight. I would shoot up to 190 when I was fighting 145. Now I don’t get past 182. That’s really the max I walk around at. But I think I could fight at 170, too. There are some fun fights there.”

Do you think we will see the fourth fight between Dustin Poirier and Conor McGregor?