Pop star Ashlee Simpson has no plans to marry boyfriend Braxton Olita because she is determined not to repeat her older sister JESSICA's mistakes. Even though the PIECES OF ME star is "absolutely in love and in a committed relationship" with Olita, the guitarist in her band, she doesn't want to marry young like Jessica, who is currently going through a highly public divorce from her estranged husband Nick Lachey. Ashlee, 21, tells Teen People magazine, "He's (Olita) the yin to my yang. People call him my little Buddha. When he comes around, everything changes... I'm more peaceful and chilled out. I honestly couldn't be more content. "We live day-to-day. Marriage is definitely not on my mind. There's a lot of growing up you do in your 20s, and I definitely want to wait until my late 20s or 30s or whenever the time is right."