My brother in law called me & invited me to come to his Grandfather's 88th B-day party. should i go?(details)

He's already at the party with my sister & nephew so he called me from his cellphone & asked me if i wanted to come. I told him i would call back & let him know. Problem is i'll have to take a long trainride to get there. I really just wanted to take the day to relax & clean my room a bit(Which i have done pretty much) but at the same time i don't really want to make my Brother In Law feel as if i didn't care about coming since i did tell him i wouldn't mind meeting his Grandfather at least once. What should i do in this situation?

Cute avatar!

If you hadn't hung up yet, I would suggest telling him you had some plans but that you appreciate the invitation and wish him a very happy birthday.

Now that you need to call him back, you could read this to him over the phone. Emphasize that you do care and still look forward to meeting him, but that given the short notice, now isn't a good time.

Whatever you do, don't forget to send birthday wishes!
You sound as though your heart is in the right spot despite the circumstances. I wish you well.

I wouldnt go. He could have invited you earlier. Dont feel guilty. But make up a very good excuse like you tried to get out of your previous engagement but it will cause big trouble if you do so sorry and you will save this date next year for his bday

Problems solved :)

Next time just be honest and tell him the truth.