Bobbiegirl learning to play with kitten Ted

When playing on his own Ted makes various little chirping sounds, I  looked this up, I think he is contented.  He is gradually teasing Bg into a playful mode, she has a fairly easy going nature although doesn’t really cuddle up to the others, I doubt she will with Ted, it is good to see her responding to his overtures.  They are playing under the cat chair, usually occupied by Rory or Greyboy and occasionally me. 

Found on the internet:
When a kitten makes a warbling sound while playing, it's usually a sign of excitement and happiness, often referred to as a "trill" or "chirp," which indicates they are having fun and are inviting you to play with them; it's essentially their way of expressing positive energy during play time.