It’s totally normal to do things while talking on the phone. It could be considered annoying or a little rude in some circumstances, like if there were a lot of background noise, or you were clearly distracted and not listening.
But that doesn’t sound like what’s going on here. The “disrespectful” act from your boyfriend is a red flag. I think you’re spot on that he’s controlling. Demanding your full attention is weird. And you are trying to avoid him getting “really upset” by not being fully transparent, which is another red flag that this might not be a good relationship.
Is your relationship long-distance? How much time do you spend together?