Grant's Heat (Shark's #4) by Angel Payne and Victoria Blue

Angel keeps the Shark's Edge series more and more interesting. Grant is Sebastian's best friend and will do anything for each other, but when Grant starts becoming friends with Rio. Now who will he stand by, Sab or Rio? But as things start changing in their lives Grant has to choose and even if he ignores the facts of what's happening he will do anything in his power to protect Rio. Rio has her own demons she's fighting, but when ever Grant's around she feels his power he seems to have to keep her calm and make her feel better about herself and her circumstances. Now they both have to find a way to keep themselves happy and to stay safe in the meantime.