Secrets? Hmmm... well when I first tried to introduce the sippy, I did it as I roused him from his nap, and that's the one he's taking most of this time too
I go in and wake him gently, pick him up out of the cot while he's still in his bag, and put the spout into his mouth (which is usually wide open, bird-like, expecting milk
) and feed him on my lap while sitting in the chair, keeping the room dark until he's finished. He does hold the handles as I was feeding him out of a bottle with handles before. We always have a nice cuddle then too
For the morning one he's wide awake and downstairs, so he doesn't take as much milk then, but I give him a choice of where to sit (again he prefers on my lap, while I'm in the chair) and he had almost all of it this morning
Letting him be a baby in my arms seems to work best for getting milk into him, whether that's in a bottle or a sippy!
Now I just have to make sure DH doesn't stuff it up again by giving DS a bottle in the daytime
Try O just after his nap and see if that works?