Hailey Baldwin's 'Lonely' Cousin Ireland Shares Adorable Throwback to Celebrate Justin Bieber Engagement

The model posted a throwback photo of her and her cousin in the bath together, captioning it, "There's gonna be one less lonely girl ... and only one lonely girl left." The note is a reference to Bieber's 2009 hit, "One Less Lonely Girl." You know, back when he was still young and adorable and doing that swoopy hairstyle everyone tried to emulate.

The picture goes even further back than that, though. The smile on Hailey's face is unmistakably hers while posing for a bathtub picture alongside sister Alaia Baldwin and Ireland. The latter is the daughter of Alec Baldwin and Kim Basinger, while Hailey and Alaia's father is Stephen Baldwin, who offered his own excited congratulations to the couple, as reported by Harper's Bazaar, even before they'd officially announced their engagement.

Alaia, who was recently married, offered her own cute reaction, too.

Reports of Beiber and Baldwin's engagement after only a few weeks of dating began to surface on Sunday, with TMZ reporting that Bieber proposed in the middle of a crowded restaurant during a trip to the Bahamas.

The couple didn't confirm the engagement until Monday afternoon, though several of their friends and relatives joined Stephen Baldwin in offering premature congratulations. Ariana Grande even chimed in with a since-deleted defense of whirlwind engagements like Bieber and Baldwin, as well as her own recent engagement to "SNL" star Pete Davidson.

Bieber posted a pic of the happy couple to Instagram, captioning it in part, "You are the love of my life Hailey Baldwin and I wouldn't want to spend it with anybody else." Baldwin took to Twitter that evening, where she wrote, "Not sure what I did in life to deserve such happiness but I am so utterly grateful to God for giving me such an incredible person to share my life with!"