Wesley swung out at Kate, who wasn't expecting it. For that matter, she wasn't expecting Wesley to do something so...juvenile.
"You...you..." Kate said, grabbing her pillow off the bed they were sharing and hitting Wesley in the chest.
Pillows flew around and around, down and stuffing falling out of the pillows all around them as they jumped on the bed and wrestled with each other.
At one point, Kate landed on top of Wesley. With the white falling all around them, she leaned down and kissed him.
That surprised Wesley, but he kissed back.
The only thing that interrupted the kiss was Cordelia banging on the wall. "Knock it off! We're trying to sleep over here!" And in the background, Wesley and Kate could clearly hear Gunn say, "Oh, Cordelia...pillow fight!"
Wesley and Kate dissolved into laughter, which led to more pillow fighting and more kissing. They had to remember to thank Angel for giving them a vacation...