New rules of engagement, and marriage

Pat Ruel is sleeping with the enemy.

USC’s offensive line coach has been for nearly five months, ever since his wife, Marti, took a job at UCLA.

Many families across the Southland have ties to both USC and UCLA, a situation that annually creates good-natured conflicts when the cross-town rivals meet on the football field. As the second-ranked Trojans prepare to play the Bruins on Saturday at the Rose Bowl, the Ruels’ situation is among the most unusual.

“I might have to sleep in a separate bed,” Pat said, feigning seriousness. “We’re best of friends and we love each other very much, but a game’s a game.”

The Ruels, who have been married for nearly 30 years, arrived in Los Angeles before the 2005 season. Their long road to the USC-UCLA rivalry included stops at seven universities and stints with four NFL teams.

Along the way, Marti earned a master’s degree and a doctorate and was most often employed at the colleges where Pat coached.

“This is the first time we’ve been at the cross-town rivals,” said Marti, an administrator for one of UCLA’s medical institutional review boards. “I don’t know how it works.”

When it comes to USC-UCLA, it often works in odd ways.

USC linebackers coach Ken Norton Jr., for example, was an All-American for the Bruins. A few years ago, former Trojans receiver Grieg Carlson shared a Westwood apartment with former Bruins quarterback David Koral and running back Manuel White during the season.

Sophomore Jimmy Miller plays tight end for USC; his younger brother Jeff is a freshman defensive end for UCLA. Justin Hickman, UCLA’s star defensive end, is the son of former USC offensive lineman Donnie Hickman. Westlake Village Oaks Christian High running back Marc Tyler, the son of former Bruin Wendell Tyler, has committed to USC.

But the rivalry’s intertwined relationships reach beyond the coaches and players.

“I think it’s kind of fun that people can be friends, brothers and sisters and people at the water cooler getting on each other about it,” USC Coach Pete Carroll said. “I think it adds a lot.”

The Ruels’ odyssey to the cross-town rivalry began at the University of Miami. Pat was a Florida native who played guard for the Hurricanes in 1971 and 1972. Marti was a cheerleader from Ohio.

After completing his eligibility, Pat spent four seasons on Miami’s coaching staff. In 1977, Lou Holtz hired him at Arkansas, where Carroll was a graduate assistant.

Pat and Marti got engaged shortly after the Razorbacks played in the 1978 Orange Bowl, then moved to Washington State, the first of five coaching stops over the next 21 years.

The Ruels spent four years in Pullman, Wash., three at Texas A&M;, three at Northern Illinois, nine at Kansas and two at Michigan State, with Pat serving as the assistant head coach and/or offensive coordinator at each of those stops.

Along the way, Marti earned a master’s degree from Texas A&M; in higher education administration. At Kansas, she completed her doctorate in educational policy and leadership, building what she described as “a nice suitcase of transferable skills.” The couple was mutually supportive of each other’s career goals.

“I probably hurt his chances of being a head coach, which I always felt he should be, and to some degree he probably affected my ability to be a vice president,” Marti said.

Said Pat: “I never wanted to hold her back and she didn’t want to hold me back. We always came together for what was best for everyone.”

Ruel joined the Detroit Lions’ staff in 2000, and then worked two seasons for the Green Bay Packers, one for the Buffalo Bills and one for the New York Giants. He took Carroll up on his offer to join the Trojans after Tim Davis left for a job with the Miami Dolphins.

After moving to the Southland, Marti temporarily put off looking for employment.

“I just knew the NFL would be back at the door,” she said. “When he said, ‘I’m at USC to stay,’ I said, ‘We’ll see when the NFL comes calling.’ ”

As Marti predicted, the Atlanta Falcons and Green Bay Packers made plays for Pat, who opted to remain at USC where their daughter, Sabra, is a sophomore.

Marti began working at UCLA at the end of June.

“I actually looked at all the area colleges and universities for possibilities,” she said. “Again, the work itself is really what I wanted to be of interest.”

Marti owns a UCLA sweatshirt and a coffee mug but mostly tries to keep a low profile among colleagues.

“You have to remember, there are two sides buttering the bread,” she said, laughing.

Over the years, Marti has not attended games at the home stadiums of opponents that were rivals. But she is likely to be at the Rose Bowl when the Trojans attempt to wrap up their third consecutive berth in the Bowl Championship Series title game.

“My daughter is trying to talk me into it,” she said. “She is slowly winning me over.”

According to Pat, there will be no doubt about his wife’s rooting interest.

“On the weekend, my wife is a Trojan,” he said. “She comes to the Trojans’ games and roots for the Trojans. When we play UCLA she’s going to be on our side.

“I just told her, ‘Don’t be inviting UCLA friends over this week.’ ”

gary.klein@latimes.com