TEAR YOU APART, by Megan Hart

From the title, it could be slasher, could be almost anything: it's not romance, it's listed on the author's website as erotica. Hard-hitting, totally frank, very explicit romance/relationship/affair between long-married mother of twin girls Elizabeth and single New York City photographer Will.
Hart is a prolific writer of everything romantic from historical to contemporary (plus some horror; perhaps it's fair to say what she doesn't write? westerns? cookbooks?). She also writes in varying degrees of "heat". This novel tells the forthright, very hot story of an engaging woman with an amazingly unconnected husband, and what happens when she meets a man she feels drawn to. Yes, it's very sexy; yes, it's explicit; yes, Elizabeth goes places many of us might not ever go (but might really want to). And, yes, it's well done enough that it's a one-sitting read. It's a 4. The sex is 4+.