Guardian Bear by Natalie Kristen

Curvy, geeky Lisa Milan has always lived for her work. She is a brilliant scientist, and research is her passion and her life. But when she discovers that her research will be used for dark, diabolical purposes, she is determined to make things right.
Things take an unexpected turn when she stops at the small town of Shadow Point.

Lisa intends to just grab some supplies for the road. Instead, she is bustled to a madcap, rowdy carnival wedding by two grandmotherly witches who simply won’t take no for an answer…
Graham Hatfield is mighty proud of himself. He helped plan this awesome carnival wedding for his sister, and now he has every intention of reaping his just rewards. He is the best man, and everyone knows that the best man always gets first pick of all the single ladies at a wedding!

But when he sees the beautiful, shy stranger standing in a corner by herself, all bets are off.
Lisa knows she has to stick to her plan and stay focused.
Time is of the essence, and she can’t afford to be distracted by the handsome best man.
But when she wakes up marked and mated, staying focused just got a whole lot harder…