When a character spreads their Breasts with their hands with the promise of or enticing someone into performing Paizuri, or even Paizuri Under Clothes. Often included with Paizuri Invitation, as it presents a spot to perform Paizuri, whether between their Unbuttoned Shirt, Bra, or Cleavage.
If you were looking for a tag about breasts which are simply spread apart, you should instead use Breasts Apart.