Overreaction or was I wrong??

So last night my siblings and I were making "40 reasons why we love you" cards for my dad's birthday. My brother started goofing off with the Alexa voice command on his Kindle. He said "hey Alexa, how do you spell Jesus?" (Jesus being pronounced in Spanish (Hay-Sus). Alexa replies with "Jesus is spelled J-E-S-U-S", but said Jesus in the English manor (Jee-sus). So we started laughing saying evidently Jesus (Spanish pronunciation) does not exist. My dad got all upset after hearing this saying we were taking the Lord's name in vain and told us to stop and was very upset. I don't get it. How was that taking the Lord's name in vain? We were just laughing at Alexa. Was he overreacting or were we actually wrong for this?

* He just tries to act religious. He watches terrible shows and everything. He doesn't go to church or read Scriptures or anything. He really isn't religious much. He is only 40 and understands Alexa and stuff perfectly.