With western birthrates circling the drain, Sydney Sweeney and her 'perfect titties' are once again fighting the good fight for humanity - this time appearing in a new ad for her new lingerie brand, Syrn, entitled "Birthday Boobs."

The 28-year-old posted the racy new ad to her Instagram page, in which she can be seen in the kitchen baking a cake - which ends up being the only thing covering her up top at one point.

At one point in the baking process, Sweeney cannot locate a towel to wipe her hands - so she uses the only available thing...

... before pulling her panties down because she made such a mess, and then slipping back into blue lingerie. 

There's a reason Sweeney keeps converting her curves into a P&L of T&A. The global lingerie market is already a roughly $100 billion business - about $99 billion in 2025, by one industry estimate, on course for something like $104 billion this year and $166 billion by 2033 - growing at a mid-to-high single-digit clip.

What used to be a low-involvement undergarment category has been re-priced as lifestyle and identity: high-margin lace and nylon, sold direct, marketed as comfort, empowerment, and desire rather than as something you hide under clothes. Celebrity founders have already shown the capital markets that this works. Kim Kardashian's Skims is a multi-billion-dollar valuation. Rihanna's Savage X Fenty turned intimates into a fashion house. Sweeney's Syrn, launched in January with backing from Coatue - the same shop whose innovation fund took a $1 billion injection from the family offices of Jeff Bezos and Michael Dell - is the latest bid for that spread: 44 bra sizes, most pieces under $100, DTC margins, and a customer-acquisition cost that is basically her Instagram.

You can see the ad on Instagram or below, for science!

Early projections put Syrn's first-year revenue around $20 million - though tabloids are already whispering it'll be a bust. We shall see!

Bonus: RIP Dolly