Mass. Gen. Laws ch. 203E, § 808: Powers to direct

Section 808. Powers to direct

(a) While a trust is revocable, the trustee may follow a direction of the settlor that is contrary to the terms of the trust.

(b) If the terms of a trust confer upon a person, other than the settlor of a revocable trust, power to direct certain actions of the trustee, the trustee shall act in accordance with an exercise of the power, unless the attempted exercise is manifestly contrary to the terms of the trust or the trustee knows the attempted exercise would constitute a serious breach of a fiduciary duty that the person holding the power owes to the beneficiaries of the trust.

(c) A person who holds a power to direct is presumptively a fiduciary who is required to act in good faith with regard to the purposes of the trust and the interests of the beneficiaries. The holder of a power to direct shall be liable for any loss that results from a breach of a fiduciary duty.