Remove Whatsapp "line busy" notification

Hey guys

So sometimes I'd like to make calls with various people but there's always this one or two annoying people would call and see "line busy" etc and start a issue.

Is there any way to change that so it say something like "connecting" instead of the person knowing im on a call.

I was thinking of making the call through fb messanger but I'm not sure what it says when someone from whatsapp calls while im on a messanger call.

Thanks

I don't think it's possible