If you thought Donna Mills had pushed her role as Abby Cunningham, the home wrecker of CBS' Knots Landing, as far as it could go, wait till next season. In September the icy blonde who lured J.R. Ewing's brother Gary into a romance behind his unsuspecting wife's back (and found time to hit the sheets with J.R. as well) finally gets what she wants: a spot alongside Gary at the altar and a crack at his 10 percent of Ewing Oil. But don't confuse the real-life actress with her torrid TV persona. While Mills shares Cunningham's passion for independence, she abhors Abby's sexual swashbuckling: "Where my morality would interfere, she just goes on."

Though Mills, 37, admits she's "always had a relationship going," for the past five years there's been only one man in her life: Richard Holland, 31, a screenwriter, advertising exec and onetime rock guitarist. They maintain separate two-bedroom houses—hers in Beverly Hills with a terraced outdoor pool, his in nearby Studio City with the requisite hot tub. "There was a point where we were practically living together," says Mills, "but when the show is shooting, I get a wake-up call at 5 a.m., and it's not fair. So what we do is stay together on weekends." Holland's explanation of their two-pad relationship differs: "The reason is that we haven't made a commitment to marriage. In the meantime we each have our own place to escape to when we need it." Donna, at least, is in no hurry to tie the knot. "I don't see any more security in being married than in not being married."

Their meeting was more Fantasy Island than Knots Landing. Holland, the son of a Los Angeles-based studio musician, had married black soul singer Chaka Khan in 1974 when he was 22. (She'd happened to rent a house next door to his place.) He became her personal manager, but after five years and one son, they split. Their wild life on the road "was too fast and too crazy," he explains. To decompress, he decided to join some chums on a get-away-from-it-all trip to Puerto Vallarta. While waiting for the flight to Mexico at the L.A. airport, Holland recalls, "I saw this woman across the room. I recognized her from TV, but I couldn't pinpoint her. She smiled back. I couldn't believe it. I even looked behind me to see who she might be smiling at."

The attraction was mutual. "I've always liked men with dark hair and dark eyes," says Mills. Although they chatted about getting together in Mexico, it wasn't until they were back in L.A. that Holland mustered the courage to call Mills for a date. He took her out to a rib house in the Valley, he says, and "everything seemed to click. She was so warm, friendly and funny. She understood my jokes, which not many people in this town do."

Mills says that Holland was just the change she had wanted. "I was dating some business types before. They're so busy getting where they're going, you look in their eyes and you don't see anything. Richard's the kind of artistic, sensitive man I've always liked."

Mills was born in Chicago as Donna Miller, the daughter of the now retired head of Union Oil's market research division and a dance teacher who encouraged her daughter to study ballet. After one year at the University of Illinois ("to please my parents"), Mills dropped out to audition for stage and dance parts in Chicago. By 1963 she was seeking stardom in Manhattan, where she landed an understudy role in Woody Allen's first play, Don't Drink the Water. A CBS casting director spotted her and offered her the role of a sexy nightclub singer in the soap opera The Secret Storm. Then in 1971 she moved to L.A. to film Play Misty for Me with Clint Eastwood. Burt Reynolds recommended her to Clint after she had played opposite Reynolds in an episode of ABC's Dan August. Eastwood looked at her Dan August rushes and hired her before he even met her. Over the next nine years she appeared in 21 TV flicks, finally landing her Knots Landing job in 1980.

Mills and Holland say they have had "no problem" with the fact that she is six years older than he—and in fact theirs is hardly the only such relationship in showbiz: Britt Ekland, 40, Juliet Mills, 41, and Joan Collins, 50, all have younger mates. Donna doesn't particularly care for Richard's love of monster-movie memorabilia (he even has a human brain in ajar and a human skeleton at his house). But she indulges his passion for sports by accompanying him to Dodger games, and he shares her love of ballet. Holland is all for Mills' career, though he frets that at times "we only see each other about five minutes out of the week. Then I start thinking, 'Hey, what about me?' But usually I'm pretty good about it.' "

Though Mills still has four years remaining in her seven-year contract, she has gained the confidence to form her own production company, Bonaparte, which has two TV projects in the works. Holland is co-producing one and she will star in both. "They are special and important to me because they show a woman the way I think women should be portrayed these days, as an independent entity, not a victim...someone who is strong and makes her way in the world because of her abilities, not because she has the right man." Even Abby (and Mary) Cunningham would approve.