Super quick BMBR because I'm at work and books 3 & 2 only cheap for a day or 2 maybe. 1 may still be free (thanks Bookbub).
In agreement with the 1 star review on Amazon.ca for book 2, these aren't the best written books with the best plots and if it's a scene without sex it's okay at best.
But if you want to laugh your ass off in some places, get some sex tips (anal too), and just plain want some foreplay, go for it.
It's like reading porn but funnier.
Edited to add: I've read more of book 2.
Bottom line: if you're in this for more than a ton of gratuitous sex between people who are all super gorgeous with perfect bodies and wondrous sexy parts, you'll be disappointed by the super cheesy writing and the huge lack of a plot. It's just porn, really.
I wouldn't spend more than a buck or two per book.