H and I have a kid together so the phone thing is a little more tricky. I answer cause I would be pretty pissed if he had my S and didn't answer on purpose. But, sometimes I miss the call and call back in a few minutes, or I say a quick hi and hand phone off to S.
Main thing it not to act like you have been waiting around for the call and not to expect ANYTHING. So hard to do, but so important. Your expectations will come through in your tone, etc. Keep it upbeat and casual.