"Because I hate him. He really pushes my buttons sometimes," Lily told Billy.
And it appears Perez's buttons were pushed too. When contacted by Access on Tuesday, he said he was surprised by Lily's use of the word "hate."
"That's sad because I don't hate her. I actually really enjoy her," he said.
During the Twitter exchange, Lily called Perez a "little parasite," and a "bitter lonely old queen," while Perez suggested the singer was only able to sell her new album, "It's Not Me, It's You," by cutting the sale price, according to the UK's Telegraph newspaper.
"It was a bit of a back and forth like school children," Perez said of the online banter. "It was very childish."
Childish or not, Lily told Billy she thinks Perez "should go away."
"I think he's just a really negative, horrible person," she continued. "And I think that he's really mean to young successful women and he calls, you know, women… trying to enjoy themselves 'sluts' and' train wrecks,' and I think it's just a really vile way of carrying on, I don't think it's responsible in any way."
When asked why he thought the two had engaged in the social networking spat, Perez blamed it on his reporting of Lily's behavior.
"She's just upset that I point out every time she's a hot mess, which is quite often. She's a bit of a boozer, actually a very big boozer and repeatedly loves to talk about drug use and she doesn't like having her own words and actions thrown back at her, but that's my job," Perez said. "That doesn't mean that I can't appreciate her music – that, I do."
But it appears for now, at least, their Twitter fracas is over.
"I just blocked him actually, so we shant be… Twittering anymore," Lily said. "I just got so irritated. I was like, 'You're blocked. Go away.'"
Blocking, however, won't deter Perez, who pointed out the Twitter tool has little after-effects.
"That means nothing other than I have to directly go to her page and I can still view what she says," he noted.
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