Not sure why they were together besides the sex. And there was a lot of sex and I believe the author was trying to enhance or explain their love to one another by using sex. (If that makes sense) However for me it didn't work, it felt like sex just stalled the real conversation from happening.
And really his stalker/abusive ex-boyfriend flies to England from Chicago and is easily told to go away...? Well he wasn't a very good stalker/abusive boyfriend if he can just be sent packing that easily.