Does remarriage automatically change decision-making responsibility or parenting time arrangements?

No. Remarriage, on its own, doesn't automatically change an existing decision-making responsibility or parenting time order or agreement - the existing arrangement remains in effect exactly as it was, and neither parent's remarriage by itself entitles the other to have it revisited. A parent doesn't gain or lose rights simply because they, or the other parent, has a new spouse.

That said, remarriage can sometimes be part of a broader set of circumstances that amounts to a material change justifying a review - for example, if it comes with a move to a new location, a significant change in the child's home environment, or new evidence relevant to the child's best interests. In those situations, it's the underlying change in circumstances that matters to a court, not the remarriage itself as a legal trigger. If you believe changes connected to a remarriage genuinely affect the child's situation, you can bring a motion to change and explain what's actually different now, but remarriage by itself isn't grounds to reopen an otherwise stable arrangement.