It happend with my son too, the same way to solve this little is

It happend with my son too, the same way to solve this little issue.

When you pick up the phone, if someone is on the phone, you will hear, then hung up. Your son has a cell, so do you... Use cell phone or wait until the phone conversion to finish...

This is the last one I will post...

Again, you can spoil your BF, but, not all the time...

Good luck!