Last week, I noticed these photos of Cameron Diaz and Justin Timberlake on the set of Bad Teacher. They appeared to be getting along very well, and JT was even doing some kind of dorky “dance” for his former lady love. I guessed at the time that they were “flirting up a storm” and that Jessica Biel should be having a massive hissy fit. And now Us Weekly agrees with me. According to Us Weekly’s cover story this week, Camy & JT “flirt openly” with each other, and that no one thinks that Jessica and JT “can survive” as a couple now. Oh, and JT “tortured” Jessica by taking the role opposite Camy. Do we really want to go with “tortured”? Really? How about “Justin waterboarded Jessica’s soul”?

Justin Timberlake and Jessica Biel’s notoriously on-and-off relationship is once again on the rocks as the singer cozies up to ex Cameron Diaz while shooting the romantic comedy Bad Teacher, reports the new Us Weekly (on newsstands now).

Multiple sources tell Us Weekly that Diaz, 37, and Timberlake, 29, flirt openly on the Valencia, Calif., set.

“He tortured Jess by taking this role, and they are reaching a breaking point,” a pal tells Us Weekly. “The truth is, I don’t know if they can survive this.”

While shooting, it’s like “old times” for Timberlake and Diaz, who dated for four years before he began romancing Biel, 28, in 2007.

There’s “lots of laughing, making fun of each other, kidding around off camera,” the source says. “She’s sassy with him — and slick, prancing around in tight clothes.”

Biel and Timberlake have been having “huge arguments” on the phone about it, says one source. The more Biel gets “territorial and upset,” another adds, Timberlake gets turned off and turns more toward Diaz, with whom he has been having “a ball.”

And though Timberlake’s mom has told Us that Biel is “one of us,” a source close to Timberlake tells Us Weekly he “won’t marry” her because “he doesn’t respect her anymore.” In fact, the source says, “when she’s not around, he’ll make fun of her to his friends.”

For more – including just how badly things changed between Biel and Timberlake after he took the role opposite Diaz; Diaz and Timberlake’s cozy on-set lunch dates; the cruel “mind games” Timberlake plays on Biel; how Biel thinks Diaz is an “evil bitch” and why Biel stays with Timberlake even though she “knows he flirts with other women” – pick up the new Us Weekly today!

[From Us Weekly]

The last half sounds totally juicy doesn’t it? My guess is that Biel does in fact think Camy is an “evil bitch” and that Camy is all “Jessica who?” I also think Justin isn’t going to marry Jessica, but maybe that has less to do with his lack of respect for her and more to do with him wanting to party and hook up with club girls and not settle down with a girl when he thinks he could do much better. Now, does Justin make fun of Jessica when she’s not around? Probably. God, I’m no fan of Jessica or anything, but Justin just seems like such a p-ssy, doesn’t he? Like, if you’re going to be such a nasty douche to your girlfriend, just f-cking man up and break up with her.

Meanhwhile, Life & Style Magazine has an interesting little tidbit about who Cameron’s seeing on the sly. Hint: not Gerard Butler, as some sources have claimed. No, supposedly Camy has been boning Alex Rodriguez. Back in February, they allegedly “bumped and grinded” or whatever, and that led to cross-country booty calls:

Cameron Diaz and Alex Rodriguez raised eyebrows when they flirted at the Creative Artists Agency Super Bowl party in Miami and now their relationship has developed into much more, an insider close to the New York Yankees slugger tells Life & Style.

“A-Rod’s with Cameron,” the insider reveals to Life & Style. “They’ve been keeping it quiet, but they’re totally together.”

When the photographers weren’t around, “they were all over each other at the CAA party,” says an onlooker. “Cameron had her hands all over Alex’s back, and they were dancing together. They also left the party together that night.” As long as they’re enjoying themselves, Cam and her man are in no rush to acknowledge their relationship.

“Alex recently arranged to fly Cameron to Miami,” a second insider tells Life & Style. “He used to fly Kate Hudson there all the time, and no one knew they were dating for a long while. Alex is very discreet.”

[From Life & Style]

“Alex is very discreet” = “Alex is boning many, many, many women besides Camy.” But does it matter? Because Cameron is probably out there with a bunch of boyfriends/hookups too. See: Timberlake’s punk ass.

Us Weekly cover courtesy of CoverAwards.