I suppose it's an angle; they know that they can't invite me to attend for a circuit overseer or a memorial because those are tedious even for them to endure. A close family member giving their first talk however... there's a gimmick there.
The upside is that my dad can never have another first talk, so it will probably be the last time that I'm invited for a while. I wasn't even invited to my other sister's baptism, so it's not like I'm invited to every uncommon occurrence; in fact it's the rarity of the invitations which has left me feeling a little flustered.
What bugged me about the invitation was that it contained the words: 'no pressure', which felt a little disingenuous. There is always pressure with this religion; it's life or death in their eyes. When you write: 'no pressure', you're writing it because you know that you are in fact applying unwelcome pressure.
Anyway, I will be going with the busy 'excuse', because it's true, I'm too busy living my life to take time out for religion.