Ex-wife wants to "correct" my son's need to phone me everyday

Hello everyone,I really need advice on this. I've been divorced for 1 year (after a 10 years marriage). We have 2 boys, 7 and 6 yo. We have alternate custody (1 week at her place, 1 week at mine). The 7yo one expressed his need to be with me more often at the beginning of the divorce, and now he's calling me every day when at his mom's. I am here for him and always will be. But my ex feel rejected in a way, and think this is not a healthy behaviour. She asked me to tell our kid that I do not want him to call me so often, which I will not do. She guilt-trip him when he phones me only to talk to me (she said to him that was not fair to her), so now he find excuses, like talking about Pokemon go, getting rare amiibos, or thinks she can't relate to. She wants to go to a family psychiatrist all 3 of us, for him to point out that this is an unhealthy behaviour. How to handle the situation for the best for him ? Thanks in advance ! via /r/Parenting https://ift.tt/2Xk3Uu7