Am I coming across loud and clear??

I haven't figured it out yet... but lately when I call to talk to my boys (when they are with my ex), I get put on speaker phone.

Now, don't get me wrong. I don't say anything that shouldn't be heard over the speaker...I mean I am talking to my 4 and 6 year old after all, but why?

Why does he need to listen to me ask questions about their day?
Why does he need to hear me tell them that I love them and miss them?
Why?

I know that he has to do the dialing.
I know that he has to be putting it on speaker.
So....why?