Do you know how annoying it is to listen to someone else talk on the phone?
I think he is being nice and trying to not bother you.
You could ask him what the deal is and take note of his reaction.
You NEED to talk to him about it. Okay. You just convinced me to date someone I know who is a great communicator. I just got out of a bad marriage where I worried about DUMB stuff and it is not worth it. My honest opinion is that there is a lot more to this story. If you are worried about this, then there are issues w/ the relationship or maybe you. I'm not trying to insult you, just saying, that seeing a therapist might make your life a lot better. Think about it. Think about if he is "the one." Because if he is not, no matter how much you love him, you are totally wasting your life.
You should be very worried! He's trying to barter you services with the bill collectors!
What is the point of worrying? Ask him. I suspect he wants to focus on the call and let you do whatever.
I had an ex who did that, because he was talking to another lady... actually a couple, and a dude, but that is obviously not the norm. I would worry about it. Since then I haven't trusted anyone who hides things. I believe in courtesy but more importantly honesty, and there is a happy median.
It could mean he is hiding something or it could mean he is being polite. Either way, it's hard to tell. Whenever he goes out, try to eavesdrop so you know what he is doing but don't jump to conclusion and accuse. Stay cool.
Personally, I do not like taking any type of call when someone else is in the same room as me. I feel it is rude. Actually, there was a psychological study that said when people hear only one side of a conversation (such as hearing someone on the phone), that it can cause stress because they subconsciously need context to feel complete. Whether they care about your phone call or not.