Journeyed there and back again
Also, it wasn't just Kip. Every PoV character was focused on sex an absurd amount of the time. Every single one. For one character it might actually make sense; it's a major theme in their stream of consciousness that the reader should be aware of. For every character? It's a major theme in the author's stream of consciousness that he couldn't manage to keep hidden for longer than 2 pages.
Another thing you mentioned about every POV, it is really only Kip's POV where it happens. You get a lot of Gavin and there is really no sex outside of the minor part with Marysia visting him. You have a lot of Teia and almost nothing as far as sex goes with her. Same with Karris.
And I will add that while you can still find it annoying to read (I did at times myself as well), keep in mind we are talking about a teenage virgin here with a hot ass wife. When I was that age more or less 90% of my day was taken up with thoughts of sex. Even at my age now it is probably close to 60 or 70% lol. So the author is giving what I would say is a pretty spot on portrayal of that type of character.