What means User busy when I call with iPhone?

i tried calling my boyfriend and line kept saying (user is busy). when i messaged him on whatsapp, he said he blocked my number as he didnt want his dad to see me calling him. is that true that its coz he blocked me or he was on another call? He was certain that he wasn’t on another call and he just blocked me temporarily… which statement could be true in this case?

[Re-Titled by Moderator]