Graduation gift for niece only or for boyfriend, too?

by FSW
(MA)

My niece just graduated college. I want to send her a check just as I did for her brother, my nephew, when he graduated several years ago.

Her boyfriend of 10 years is in the same graduating class as she is. I will be sending him a card. As we are not related to him (at least, not yet), I am not sure if I should give him just a card or a monetary gift, as well. We have only met him a couple of times but clearly, they are a serious couple. They live together so they will see each others' cards and the gift we will include with hers.

I feel awkward not giving him a gift because they are a couple but should I only do it because we are giving her a gift? Not sure how to handle this properly.

Thanks for your help on this.