Easiest way to treat someone on our sailing to dinner

We are sailing the Jewel in Oct. Our BIL and SIL are joining us on this trip with their 3 children. We would like to treat them to a night out alone in a specialty restaurant so they can have some alone time (which they never get with 3 kids) and we are wondering what is the best way to do this.......should we just buy them obc to cover the cost (not sure which restaurant they would want) or can we have our concierge put the bill on our card (we are in a suite.....they are balcony).? Or are there any other suggestions?

Maybe I am over thinking this?

Thanks for any help:)

Such a nice thing to do. We just went to the restaurant after we boarded and booked reservations for our in-laws and told them to charge my card (I had it with me, of course). They went and when the bill came they told them it was compliments of us...... Hope this helps. =)

You can also pre-order a gift, such as OBC, which you purchase. They will receive a coupon and a note in their stateroom.

You will want to be logged out of NCL.com, then visit here...

https://www.ncl.com/onboard-gifts