u/Alternative-Lie-9113

I’m looking for a series

In the first book, the girl falls in love with her brother's friend.

In the second or third book, the focus shifts to the brother. He is part of a group where he always has three-ways with another guy in their circle. However, he meets a waitress/caterer at an event and becomes obsessed with her. He moves her in and ends the three-way dynamic with the third friend to be with her.

The plot involves the waitress’s foster brother, whom she is always trying to help. It turns out he is actually in love with her and eventually tries to kidnap her.

Does anyone recognize this series or book?