Facts: Mother and Father are the divorced parents of one child. Both are also lawyers. At the time of divorce, Mother received 261 days of parenting time while Father received 104 days.
After their divorce, Father married Stepmother, and they later had a child together. Father’s relationship with Stepmother began prior to his divorce from Mother. As such, Mother’s relationship with Father and Stepmother was strained.
Father petitioned to change custody because Mother caused a hostile environment for the child whenever Father and Stepmother were present, called Stepmother obscene names in the child’s presence, and was alienating the child from Father.
Mother admitted that Father’s remarriage “dramatically impacted” their relationship.
The trial court entered a temporary restraining order prohibiting Mother from discussing the litigation with the child and from creating a hostile environment for the child while Father and Stepmother were present.
The proof showed that during an exchange of the child, Father took the child on an out-of-state trip without giving Mother an itinerary as required by the parenting plan. When he returned the child, Mother told the child, “Daddy kidnapped you.”
The proof also showed that Mother often threatened Father with the denial of parenting time and once demanded that Father sign an agreement requiring that Stepmother have no contact with the child.
Other evidence showed Mother talking about Father’s extramarital affair in the presence of the child.
Father also submitted a video from the child’s T-ball game where, in the child’s presence, Mother hurled insults like “bitch,” “whore,” and “mistress” at Stepmother, refused to allow the child to participate in the game because of Stepmother’s presence, and told the child that Father did not love him. The child can be seen crying and hiding behind a tree during this incident.
Other videos showed Mother repeatedly discussing the litigation in front of the child.
Conversely, there was also evidence showing that Father called Mother “a terrible mother” in front of the child and once described Mother as a “Grumpasaurus.”
Despite this, the proof showed the child was performing well in school, was involved in many activities, and was strongly bonded to Mother.
The trial court found that changing custody to Father was in the child’s best interest. Mother’s parenting time was suspended for 60 days, during which Mother was ordered to participate in therapy with a court-appointed therapist. Mother could then petition the court to implement the parenting plan awarding her 100 days of parenting time.
Mother appealed.
On Appeal: The Court of Appeals affirmed the trial court.
When considering a petition to modify a parenting plan, the threshold issue is whether a material change in circumstances has occurred since the entry of the parenting plan.
There are no bright-line rules for determining when a change of circumstances should be deemed material enough to warrant changing an existing custody arrangement. The following principles guide the inquiry:

• the change in circumstances must involve either the child’s circumstances or a parent’s circumstances that affect the child’s well-being;
• the changed circumstances must have arisen after the entry of the parenting plan sought to be modified; and
• the change in circumstances must affect the child’s well-being in some material way.

If the person seeking to modify the parenting plan can demonstrate a material change in circumstances, the trial court must then re-examine the comparative fitness of the parents and analyze the child’s best interest.
Determining a child’s best interest is a fact-sensitive inquiry that does not call for a rote examination of each of the relevant factors and then a determination of whether the sum of the factors tips in favor of or against the parent. The relevancy and weight to be given each factor depends on the unique facts of each case. The determination of what is in a child’s best interest could turn on a single factor.
The Court found that Mother’s behavior toward Father and Stepmother caused direct harm to the child:

[W]e do not discount that Father has exhibited some inappropriate behavior in this case. In the totality of the circumstances, however, Mother’s complete lack of judgment with regard to her behavior towards Father and Stepmother in the child’s presence far overwhelms the rather limited evidence concerning Father’s misconduct. Here, Mother has engaged in repeated outbursts that have caused the child to fear being around Stepmother in Mother’s presence. Regardless of Mother’s feelings on this issue, Stepmother is a part of the child’s life.
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Here, Mother’s behavior towards Father and Stepmother concerning their marriage can be described as nothing short of abusive. In addition to hurling vicious and inappropriate names at Stepmother, Mother has also threatened Father’s continued involvement with the child due to Stepmother’s presence. We cannot conclude that Mother’s action indirectly exposing the child to the abuse directed at Stepmother and Father does not also constitute a form of emotional abuse.
* * * * *
We discern no abuse of discretion in the trial court’s decision to name Father primary residential parent and decrease Mother’s time with the child in accordance with the permanent parenting plan ordered by the trial court. Here, Mother’s frequent outbursts have clearly caused the child emotional distress and Mother continued in her negative behavior even after agreeing to be bound by the restraining order in this case. In our view, it should not be necessary for parents, particularly those who are attorneys and should be well-versed in Tennessee domestic law, to be ordered by judges not to denigrate the child’s other parent and his or her life in the child’s presence. The nature of divorce often means that a child will be outside one parent’s control for significant periods of time, sometimes interacting with other individuals. Like it or not, Stepmother is a part of the child’s life. As found by the trial court, any purported fears about Stepmother’s character and her interactions around the child are completely unsupported by the evidence. Mother’s behavior here toward Father and Stepmother was therefore not only unacceptable, it directly caused the child emotional harm. The fact that the child has not needed counseling or had visible long-term negative effects is simply not dispositive of which parent is better able to care for the child at this time. Here, Mother has shown a marked inability to facilitate the child’s relationship with Father and Father’s family.

The trial court’s change of custody was affirmed.
K.O.’s Comment: All parents and stepparents would do well to listen to my recent podcast on effective coparenting between mothers and stepmothers.
Fiala v. Fiala (Tennessee Court of Appeals, Middle Section, September 21, 2018).