The unlikely pairing of Brit actress Sienna Miller, best known for dating Jude Law back when he was marginally hot, and her alleged fiance, “Notting Hill” actor Rhys Ifans, may be on the rocks. Rumors are flying that Sienna’s work schedule and her trademark flirting and partying are causing Rhys to show his jealous streak- and Sienna is ready to call the whole thing off.

Sienna Miller and Rhys Ifans are reportedly on the verge of a split.

Hot on the heels of engagement rumors, Sienna is said to be struggling to cope with Rhys’ possessiveness; and his behavior reminds her of ‘controlling’ ex-boyfriend Jude Law.

A source says, “Rhys gets very jealous – he hates her socializing with other men and always wants to know where she is and who she’s with. During a row she yelled at him: ‘It’s just like being with Jude’.

“Rhys freaked out, because he prides himself on being the laid-back opposite of Jude. But he just gets worked up seeing men admiring his girlfriend and trying to hit on her.”

Tensions between the pair have worsened due to work commitments. Sienna has been filming GI Joe in America while Rhys has been working in the UK.

“They had a huge bust up recently,” the friend added.

“Sienna promised to spend a week with Rhys. He arranged his filming schedule, but at the last minute she canceled her trip, saying she had to work. Rhys hit the roof when he called her and found out she was partying in LA.”

Another source said, “It’s awful but everyone who knows them can just see it coming a mile off.

“Rhys still seems madly in love with her but everyone’s speculating Sienna has grown out of the relationship.”

“It’s almost painful to see them gone from being this 24/7 love-fest to him looking as if he’s struggling to keep her attention. It’s so sad.”

[From Showbiz Spy]

It’s got to be difficult to date Sienna Miller- especially when you look like a hobo. But Rhys had to know what he was in for with Sienna- the woman is a serial skank who changes men like most of us change our underpants, and probably leaves them worse for wear. As for Sienna, she probably thinks she could do better than Rhys, but if she were smart, she’d realize that she peaked with Jude Law, and it’s all downhill from there.

Picture note by Celebitchy: Sienna Miller and Rhys Ifans are shown on 5/10/08 out in London. They went to lunch and stopped at a store called “Dragons” which looks suspiciously like a baby store but also has non-child furniture. Sienna is said to have bought a stuffed pig.