90210 beauty JENNIE and TWILIGHT hunk ex-hubby war over his new honey THOR star JAIMIE ALEXANDER.

 AFTER an amicable divorce, actress Jennie Garth and her ex-hubby Peter Facinelli are at each other’s throats!

Sources say the “90210” beauty, 41, and the “Twilight Saga” star, 39, con­tinue to wage war over his year-long romance with actress Jaimie Alexander, 29.

“Jennie has tried her best to get along with Jaimie, but Peter’s romance with her just grates on her nerves,” said a source.

In the latest ruckus, Peter and Jaimie – who co-starred in the 2011 film “Loosies” – turned heads by getting overly affectionate with each other at a recent Big Apple event.

 She went braless in a revealing white blazer and, between smooches, answered a question about Peter’s most romantic gestures toward her by coquettishly saying they were “too graphic” to discuss.

Jennie tore into Peter over the public lovefest, saying it set a bad example for their daughters, Luca, 16, Lola, 10, and 7-year-old Fiona, said an insider.

 “But Peter believes what he does with Jaimie is none of Jennie’s business,” said the source.

Adding to Jennie’s ire, Peter and Jaimie have settled into a $2 million home on the same street in Toluca Lake, Calif., where Jennie, Peter and their girls used to live.

“It’s a knife in Jennie’s heart,” said the source.

 “But Peter thought it was a great idea for their daughters to stay in the same neighborhood.”

While Jennie has been dating million­aire Internet mogul Michael Shimbo, “she and Pe­ter just never seem to get over the hump,” said the source.

“Just when it looks like they’ve made peace, one of them does something to antagonize the other.”