A non-custodial parent is responsible to pay child support whether or not the custodial parent has a boyfriend or a husband or not. This responsibility continues until the child reaches the age of 18 years unless the child dies or the court takes some action to end that responsibility.
no
NO!
Generally, no.
no
yes
no
Yes, depending on state laws. But, a motion to modify can be presented to the court. see links
Yes, it can. Moving in with the other parent is grounds for "flipping" child support payments. However, this must be done by court order.
Yes
no
Child support needs to be decided on by the court. In most cases, the noncustodial parent is responsible for something. If the custodial parent makes considerably more than the noncustodial parent, monies many not even be exchanged. To resolve this issue, it is best to file papers at your court house.
Yes. They are still the child's parent and responsible for supporting their child.