Jessica Simpson took to Instagram with new pictures of kids Maxwell and Ace to wish fiance Eric Johnson a happy Father's Day Credit: Courtesy of Jessica Simpson

Jessica Simpson's kids get cuter every day! The fashion mogul and Weight Watchers spokesperson, 33, took to Instagram on Sunday, June 15, to share three new snaps of her precious little onesjust in time for Father's Day!

One photo shows son Ace, 12 months, giggling and being lifted into the air by Simpson's fiance Eric Johnson. "This is just what they do," the proud mom captioned the picture. "Ace loves you Eric! Happy Father's Day!"

Alongside another postthis one a split shot of daughter Maxwell, 2, grinning and hugging a treeshe wrote, "Maxi is a true Daddy's girl. We love you Eric! Happy Father's Day!!!!"

The engaged star also paid tribute to her own father, Joe Simpson, with a snapshot of Joe making a funny face at his granddaughter. "Happy Father's Day @papjoeentertainment XOXO," she tweeted.

Simpson has been all about showing the love via social media lately. Last month, in honor of her four-year anniversary with former NFL player Johnson, 34, she shared a picture of them posing together at an art studio, with the caption: "I can't wait to marry you!!! Best 4yrs of my life!!!" 

Alongside another shot of them kissing, she added, "Happy 4yr anniversary baby!! I am so honored to be the mother of your babies and loved by you every moment." 

As Us Weekly previously reported, the couple will tie the knot in a wedding over the July 4th weekend. They recently celebrated their impending marriage with a co-ed bachelor/bachelorette bash in L.A.