I'm upset that my boyfriend wants to sell the Christmas gift I gave him
Did he not like your gift? Why is he selling it?
He didn't like the style
You shouldn't tell others what to do with their gifts. If something doesn't fit their style you should be more aware next time.
It's okay, I just got to sell it faster and make some cash.
Well, it's a gift you already have given and it is their possession now, so it is wrong for you to take it back and get money in return. I hope that you just ask your boyfriend what gift you want to buy for him next time, so that he will not return it or sell it in the future.