The menage includes half of the twins (Killian) in the family and his best friends from high school: Justin and Lily. Justin and Killian spent a number of years in the army in Iraq; Lily got an PhD in Marine Biology in California. Everyone is back in Baltimore and attending a 10 year high school reunion when Lily proposes something she's been wanting to do since high school. See, Justin and K had a rep for sharing girls even back then, and Lily has been pining for the pair forever. The initial deal is for one night, then one weekend. They are interrupted by Lily's younger brother Chad and Killian's brother Sean, who had been invited over to watch the ball game on Sunday, which went completely out of everyone's head, what with all the sex that had been happening since Friday night.
No guy-on-guy action, unless you count the description of (hey, if you're too young to be reading this, stop right now.) the one-hesitates-to-call-it-climatic double penetration scene near the end when the guys are noticing they can feel each other through Lily. Ahem.
I have to hand it to Carr: she handled the "coming out" of the threesome really well, particularly considering that she hasn't had a gay or lesbian couple as even a background character in the series. When Sean is talking to Justin about whether the morose threesome can turn a 2 night fantasy into a lifetime of looooovvvveee, he gestures to a biracial couple and a gay couple in the bar, and points out that if the world can change enough to accept them, it might one day make a triad part of normal, too (altho the term triad is not used). That's a normalization strategy destined to make this real popular among the poly community.
Other aspects of the novel, not so much. Justin, in particular, seems a little concerned whether all this makes him "gay". Er, homophobic, much? Besides, it wouldn't make him gay anyway; it might make him bi. Carr plays up the whole good girl/bad girl theme more than I care for, and the nicknames the guys have for Lily ("sweetness", "baby girl") were a little grating. I have to suspect, however, that Carr knew she was doing that. At one point she describes Lily as squirming like a toddler in church, and if _that_ isn't an intentionally shocking simile to use in a sex scene, I don't know what would be.
Friday shows us Ewan making a play for Natalie, photographer of Sky (and now Teagan). She's got some serious mental health issues as a result of her sister dying some years ago and a generally unloving family (not necessarily abuse -- just real standoffish). Natalie lives for sarcasm, which Ewan admires, but he's worried about her and when Nat says she wishes she weren't always the one taking the pictures but sometimes the one in the picture. Ewan gives her a week of being in the middle of her life: taking her out one night with Riley and Aaron, romancing her, taking her fishing. She gets a bit frantic and attempts to back out when she realizes the depth of her attachment to Ewan, but pictures save the day -- taken by Ewan, of Natalie, living her life.
These books aren't going to be for everyone (even I would not let a prepubescent kid near them): you have to have some kind of e-reader (altho you can get free ones for a regular computer, and you don't have to get this through kindle -- EC offers it elsewhere and in various formats), you have to be interested in, not just okay with, very detailed sex scenes used to describe a developing relationship. But if this is the kind of thing you like, it's done really well. I'll keep reading the series, and will probably try some of Carr's other books when it is complete.