Headed For A Split? ‘RHOBH’ Star Adrienne Maloof’s Boy Toy Jacob Busch Getting Close To Neighbor Paris Hilton — Adrienne ‘Not Happy'

They said it wouldn’t last. And increasingly, it seems like 53-year-old Real Housewives of Beverly Hills star, Adrienne Maloof and, boy toy, Jacob Busch, 25, might not make it to the altar! RadarOnline.com has exclusively learned that Busch has raised eyebrows in Maloof’s gated community by spending a lot of time at neighbor Paris Hilton's mansion — and Maloof is not happy!

"Adrienne's boyfriend, Jacob, has been seen going over to Paris' house, which is very close to hers,” an insider reveals. “He never goes with Adrienne, and it's obvious he isn't going over there to borrow some sugar, or milk!”

Seemingly trying to cover his tracks, "Jacob stops by Adrienne's house when he knows she won't be there, and then he goes over to Paris' house instead,” the source claimed.

“Jacob and Paris have definitely been hanging out,” said the source "Word has gotten back to Adrienne about the visits, and needless to say, she isn't happy about it.”

“Jacob insists nothing is going on other than friendship with Paris, and has expressed nothing but love for Adrienne, but all talk of marriage is now on hold,” the source said.

Maloof first met Busch while attending a party for Robert Shapiro in Beverly Hills on September 7, 2013, and the pair have been together ever since.

Although Maloof has been wearing a diamond ring that Busch gave to her on Valentine’s Day, a source previously told us the pair, “are not yet engaged, although she leads everyone to believe they are by wearing his ring on her wedding ring finger!”

Hilton, 33, has been single since breaking up with younger boyfriend, model River Viiperi, 23, several months ago.