Not a lot of story to judge, will pick up any sequel just to see where it goes. There was a few dialogue issues and using quotation marks.
I'm not a fan of a book starting on a sex scene, this was wasn't bad, there was build up and anxiety, not sure I felt the realism in the story though. Although I know it's definitely feasible to happen, the story seemed forced, if that makes sense.
I also feel like if a boyfriend consented to having a threesome, knowing who the guy was before he rang the doorbell would be a definite.