This book is exploring the idea of aliens mingling with humans. The aliens are not necessarily threatening, though almost. There is some internal squabbling of leadership and Earth is caught in the middle.
The book doesn’t revolve around a romance, but it is highly prevalent. The main character falls in love with a girl, who he finds out is an alien from the group that came to Earth. Then later finds out she is a physically powerful shapeshifter whose natural shape is closer to that of… a black bear or cougar if I remember correctly. It is very much kinky.
The main character helps one of the two alien brothers vying for control. The one who wants to include Earth peacefully. What the other brother wants I don’t remember, but he destroys a city to make a point. A little conflict with his brother who had a thing for the alien girl too.
It’s a good read. Definitely, if you are into kinky alien romance… The book is a stand-alone novel.