Jessica Simpson and Eric Johnson have lunch at a Santa Monica restaurant on June 22, 2013. Credit: Splash News

Jessica Simpson was feeling colorful on Saturday, June 22, showing off her growing baby bump in a flowing tie-dye dress while grabbing lunch with her fiance Eric Johnson in Santa Monica, Calif.

Skipping heels, the Fashion Star mentor, pregnant with her second child, wore jeweled flip flops with the beaded dress, accessorizing with a pink canvas bag and sunglasses. The 32-year-old held hands with her former NFL player beau, who kept his look casual with flip flops, khaki shorts, brown T-shirt and a Boston Redsox hat.

Due to give birth to a son this summer, Simpson looked ready to pop while walking into the restaurant.

Post-baby, a source tells Us Weekly that the singer hopes to finally tie the knot with Johnson, 33, whom she got engaged to in 2010.

"[She] was telling friends she wanted to get married a few months after the baby is born," a source told Us. "Let's have this wedding already before I get pregnant with another one!'"

The couple are already parents to daughter Maxwell, 13 months.