Billie Eilish smiles after a workout in Los Angeles after

Billie Eilish smiles after a workout in Los Angeles… after causing outrage on Halloween

Billie Eilish smiles after a workout in Los Angeles… after causing outrage with her Halloween costume with boyfriend Jesse Rutherford

Just days after causing outrage from many fans over her age-related Halloween costume with her older boyfriend Jesse Rutherford, Billie Eilish was beaming all over the place.

The 20-year-old pop star was seen chatting with a friend after leaving a training session in Los Angeles on Wednesday.

The outing came just days after she made her relationship with Jesse Rutherford an “Instagram official,” though her baby costume and her 31-year-old boyfriend’s costume — which poked fun at their age difference — didn’t make much sense to many fans laughter were.

Smiling Billie: Just days after causing outrage from many fans over her age-related Halloween costume with her older boyfriend Jesse Rutherford, Billie Eilish smiled while out and about

Smiling Billie: Just days after causing outrage from many fans over her age-related Halloween costume with her older boyfriend Jesse Rutherford, Billie Eilish smiled while out and about

Eilish was spotted training in a black short-sleeved t-shirt with black cycling shorts.

She also wore a black baseball cap while carrying her phone and a large green water bottle.

The singer completed her look with a pair of black trainers and black socks for her weekday workout.

Billie' look: Eilish was spotted training in a black short-sleeved t-shirt with black cycling shorts

Billie’ look: Eilish was spotted training in a black short-sleeved t-shirt with black cycling shorts

Eilish used the weekend’s Halloween celebrations as an opportunity to take to Instagram with boyfriend Jesse Rutherford.

She shared a series of photos and videos from her Halloween weekend on Tuesday, the latest of which was her dressed up as a baby and her singer-songwriter boyfriend dressed up as an old man.

The photo was shared widely on social media, with many fans expressing their frustration and disgust at the couple poking fun at their 11-year age difference.

Age gap: She shared a series of photos and videos from their Halloween weekend on Tuesday, the last of which was of her dressed up as a baby and her singer-songwriter boyfriend dressed up as an old man

Age gap: She shared a series of photos and videos from their Halloween weekend on Tuesday, the last of which was of her dressed up as a baby and her singer-songwriter boyfriend dressed up as an old man

Before Eilish posted the photo, other images from a Halloween party she attended with her brother Finneas were shared by PopCrave, and many fans responded to this Twitter post.

“Oh no that’s sick,” added Twitter user @barswt, while @gremlikegremlin shared a meme of iCarly’s Miranda Cosgrove with a hand over his mouth.

@sandalwoodlove added, “This Billie Eilish costume is extremely disturbing and I hate it every time it crosses my timeline.”

Joke: Before Eilish posted the photo, other images from a Halloween party she attended with her brother Finneas were shared by PopCrave, and many fans reacted to this Twitter post

Joke: Before Eilish posted the photo, other images from a Halloween party she attended with her brother Finneas were shared by PopCrave, and many fans reacted to this Twitter post

Sick:

Sick: “Oh no that’s sick,” added Twitter user @barswt

Meme: @gremlikegremlin shared a meme of iCarly's Miranda Cosgrove with a hand over her mouth

Meme: @gremlikegremlin shared a meme of iCarly’s Miranda Cosgrove with a hand over her mouth

Disturbing: @sandalwoodlove added,

Disturbing: @sandalwoodlove added, “This Billie Eilish costume is extremely disturbing and I absolutely hate it every time it crosses my timeline.”

@madeofcinnamonn added: “Billie Eilish and Jessie Rutherford’s matching Halloween costumes are incredibly sick and twisted – especially with their age difference and power imbalance. It’s not funny or fancy, it’s not fun, it’s disturbing, and the adults in her life are failing her again.

@tired_ole_wench added: “No no @billieeilish wyf did you think? This is worrying.”

@inlovewithouid added: “I mean they troll people who have unnecessary opinions about their relationship. So in a way you’re proving their point and making it even funnier.

Twisted: @madeofcinnamonn added,

Twisted: @madeofcinnamonn added, “Billie Eilish and Jessie Rutherford’s matching Halloween costumes are incredibly sick and twisted – especially with their age difference and power imbalance. It’s not funny or fancy, it’s not fun, it’s disturbing, and the adults in her life are failing her again.

Nooo: @tired_ole_wench added:

Nooo: @tired_ole_wench added: “Nooo no @billieeilish wyf did you think? That’s worrying’

Point: @inlovewithouid added,

Point: @inlovewithouid added, “I mean they troll people who have unnecessary opinions about their relationship. In a way, you prove their point and make it even funnier.