Dragon of Glass by Zoe Chant

Jingle bells and magic spells
Daniella has everything she needs for a quiet Christmas at home with her dog, Fabio. She’s got way too much food, a real Christmas tree, a cable station streaming non-stop holiday movies, and even fruitcake. All she needs now is an ornament for her tree…
But what she gets instead is a glass dragon imprisoning a gorgeous naked guy from another world.
Trey, fae dragon knight, protector of the realm, and defender of the fallen crown, has finally been released from his spell by a kiss from a beautiful woman (and her noble hound). His power hobbled, his dragon form embarrassingly small, he finds himself navigating a strange world of wonders like televisions, refrigerators, and ham sandwiches, absolutely enspelled by a woman who swears she isn’t a witch.
Then Trey discovers that the enemy from his homeworld is starting to spill into Daniella’s and it will take power he no longer has to protect her… power that is locked in Daniella’s heart.