Boy Name Question

Sorry this is long, but we will confirm on Tuesday if we're having a boy. If so I think we have our name picked out, but I wanted to get some random opinions. My husband is John Anthony Jr. So instead of doing a third he wanted to use John as the first name and we like David as the second name and call him John David all the time.  David is my step dad who has been part of my life since I was 8. We also just like the meaning of the name David and the way it flows with the name John. Wondering if this is a slap in the face to my real dad. We don't have a great relationship but he is oblivious to that. My question is should I have to tell my dad about the name before hand, lie and say it's my husbands family name, tell him we just like the name or do I owe him an explanation at all? If this doesn't make sense just let me know. Appreciate the feedback!!!