Hilary Duff's boyfriend Matthew Koma shows off adorable new tattoo honoring their daughter Banks and her son Luca

He welcomed his baby girl Banks just 13 months ago.

And Matthew Koma commemorated the daughter he shares with Hilary Duff on Tuesday in an adorable tattoo shared to Instagram. 

The new ink showed an outline of Banks holding hands with her big brother Luca, seven. 

Tatt's lovely: Matthew Koma commemorated the daughter he shares with Hilary Duff on Tuesday in an adorable tattoo shared to Instagram

Tatt's lovely: Matthew Koma commemorated the daughter he shares with Hilary Duff on Tuesday in an adorable tattoo shared to Instagram

The 32-year-old musician captioned the sweet post, 'Luca (7) and Banks (1) holding hands just after her 1st birthday. Thank you @curtmontgomerytattoos for engraving my kids.'

Luca Cruz Comrie is the son Hilary shares with her ex-husband, Canadian ice hockey player Mike Comrie.

The pair finalized their divorce in 2016, before 32-year-old Duff began dating Koma in January 2017. 

Family: She shares Banks with her fiance, Winnetka Bowling League rocker Matthew Koma, 32. Son Luca seen on the right

Family: She shares Banks with her fiance, Winnetka Bowling League rocker Matthew Koma, 32. Son Luca seen on the right

On Sunday, Duff showed off baby Banks as they attended a party for Happy Little Camper brand of natural baby diapers.

The actress held a fun garden party to celebrate the launch in Los Angeles. 

This comes days after the pinup was seen shooting her new Lizzie McGuire series for Disney+. 

Mommy duty: Hilary Duff chased 13-month-old baby Banks at he garden party she hosted to launch her new Happy Little Camper brand of diapers on Sunday  

Cute dress: Banks had on a beige and white dress with grey socks and yellow bows

Cute dress: Banks had on a beige and white dress with grey socks and yellow bows

The party featured a band singing children's songs as the young guests shook tambourines and clicked drumsticks together in time to the music.

There was a shallow pool filled with blue plastic balls for the youngsters to play in.

A giant tub of soapy mixture with two people creating giant bubbles was also popular.

And guests were invited to stick their faces through a giant poster showing them as babies on a camping trip for fun photos of the event.

Gotcha: Banks stared happily at her mom after Hilary caught up with her to pose in front of her Happy Little Camper hoarding

Fun times on the brick: The young mom spun her little girl around as she smiled

Fun times on the brick: The young mom spun her little girl around as she smiled

Break time: She sat on her legs as she modeled a pink top and beige slacks

Break time: She sat on her legs as she modeled a pink top and beige slacks

Getting into the beats: Well, she is the daughter of Winnetka Bowling League rocker Matthew Koma, 32

Getting into the beats: Well, she is the daughter of Winnetka Bowling League rocker Matthew Koma, 32

Hilary shared a slew of snaps from the day.

And in one, she wrote this message: 'Motherhood has held my hardest and most rewarding days, which is why I’m so excited to introduce all the other moms and dads out there to my company, @happylittlecamperbaby!

'Safe and natural products shouldn’t be something you’re worrying about when you’re being a parent.'

Quitea sight: Hilary and her son Luca, seven, whom she shares with ex-husband Mike Comrie, had fun sticking their faces through the holes of this hoarding for snaps

Quitea sight: Hilary and her son Luca, seven, whom she shares with ex-husband Mike Comrie, had fun sticking their faces through the holes of this hoarding for snaps 

Safe products: Hilary hopes moms will want her all-natural baby wipes as well as her diapers

Safe products: Hilary hopes moms will want her all-natural baby wipes as well as her diapers

She shares Banks with her fiance, Winnetka Bowling League rocker Matthew Koma, 32.

He popped the question to his love earlier this year and the couple announced their engagement on May 9.  

Last week the siren was seen filming her new Lizzie McGuire series. Back in August, Duff announced the news at the Disney D23 Expo.

On set: Last week the siren was seen filming her new Lizzie McGuire series. Back in August, Duff announced the news at the Disney D23 Expo

On set: Last week the siren was seen filming her new Lizzie McGuire series. Back in August, Duff announced the news at the Disney D23 Expo

 

Hilary Duff's boyfriend Matthew Koma shows off adorable new tattoo honoring their daughter Banks

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