Christina Aguilera gave a spot-on impersonation of rumored pop rival Britney Spears. The singer made an appearance on The Tonight Show, where she also gave musical impersonations of Cher and Shakira, according to Us Weekly. It brought up the age old question: Are Christina Aguilera and Britney Spears in a feud? Even though the singers have shaded each other in the past, they've been supportive of each other as of late.

Spears, 33, first hinted in a 2005 blog post titled "Truth Be Told" that she actually likes Aguilera, 34. Her team wrote, "Britney would love to be close with Christina again. In fact, Britney recently wrote Christina letter telling her how happy and beautiful Christina looks lately."

Christina, formerly known as "Xtina," shaded Britney before her wedding to now ex-husband Kevin Federline. In a 2004 interview with Us Weekly, the diva said, "I know Britney. She's not trailer trash, but she sure acts that way." Christina also shaded Britney's engagement ring. "I can't believe that girl bought her own engagement ring! I've seen it, up close. It looks like she got it on QVC."

That's not all that Aguilera said about Spears in the early 2000s. In a 2003 interview with Blender magazine, Aguilera called Spears "distant" and "a lost little girl." She called out the pop siren for her strange behavior during their rehearsals for their iconic MTV VMAs performance with Madonna. "Every time I tried to start a conversation with her – well, let's just say she seemed nervous the whole time. She seems to me like a lost little girl, someone who desperately needs guidance."

Britney must've read Christina's cruel comments, since she retaliated against the singer in the January, 2004, issue of Blender. She said that she didn't see Christina for two years where they met up at a nightclub and nearly kissed. "She comes up to me in a club in front of all these people and tries to put her tongue down my throat!" Britney tells the magazine, "I say, 'It's good to see you,' and she goes, 'Well, you're not being real with me.' I was like, 'Well, Christina, what's your definition of real? Going up to girls and kissing them after you haven't seen them for two years?'"

The then "Slave 4 U" singer also slammed the "Dirrty" singer for her cruel comments. Britney said, "A lost girl? I think it's probably the other way around. I can't believe she said that about me. When someone has been rude to you so many times, it's like, 'You know what, Christina, I'm really not about the fake anymore.'"

According to Us Weekly, Aguilera and Spears have known each other since 1993, where they both got their start on The All-New Mickey Mouse Club, also known as The MMC. They appeared in various skits and performances on the kids show. Aguilera and Spears both ruled the pop charts in 1998 and '99 with their hit singles "Genie in a Bottle" and "…Baby One More Time."

So, what did Britney really think of Christina's impression? A source close to Hollywood Life says that Britney not only knows about, but she loved it as well.

"Britney saw it and thought it was pretty great, they have had their issues in the past but Brit thought is was light-hearted and fun and she never thought it was mean-spirited at all. Brit is happy she did it so well."

Christina Aguilera and Britney Spears have put their differences aside over the years. The pop singers have showed their support for each other on Twitter several times. It looks like they've grown up and have moved on from the drama. Rivaling singers like Taylor Swift and Katy Perry will want to take notes.

Do you believe that Christina Aguilera and Britney Spears are now on good terms with each other?

[Image: Frank Micelotta / Stringer]