Why is my boyfriend muting me when we’re on the phone together?

Sometimes my bf and I will talk on the phone while watching the same tv show. It makes him feel like we’re watching tv together since he works late until during the week and we can’t always see each other. Tonight when we were on the phone together the sound kept going in and out so I could tell that I was put on mute. I would ask him a question, he would respond and then I would hear his tv and air conditioner in the background. After he answered the sound would go out again. I asked him why he kept putting me on mute and then he lied saying he didn’t and its his phone acting up. Then he said “Everything is my fault” and “You’re always blaming me”. I think it’s odd do you think somethings up?