Would you be disappointed if you received money as a Christmas gift (especially in the West)?

This is my first Christmas in the UK, and I’m spending it with my boyfriend at his parents’ house. It was a very last-minute decision, as I was quite indecisive about whether to go back home to Hong Kong for the winter break or stay here. I arrived at my boyfriend’s parents’ place just yesterday on a whim. I didn’t have time to buy any presents, so I’ve decided to give my boyfriend’s dad, mum, and little brother £100 each in some nice envelopes, which is the standard Chinese way. Obviously, my boyfriend says I don’t have to give anything, but I’d feel bad turning up empty-handed at Christmas. Either way, I’ve been told by some of my British friends that cash can be seen as a bit too impersonal or lazy as a gift here.