Three stars is somewhat generous.
This is a fairly generic marriage-of-convenience/marriage-to-save-a-reputation story where the bride and groom love each other but don't have the guts to tell the other one how they feel, so they spend the entire book being "proud" and hurting each other's feelings.
Marcus, who's an earl in his mid-30s and a dedicated philanderer with no interest in marriage (and with weird mommy issues* which make him AFRAID TO LOVE), discovers he's inherited an estate from a distant relative. When he visits the estate, he finds a very young woman, Meg, who is also a relative of the now-dead estate owner (presumably on the other side of the family. Meg and Marcus are not actually related to each other) who has been living there as an unpaid servant for years.
Spoiler: When she was 10, Meg's parents died in a murder-suicide when her father caught his wife, Meg's mother, with a lover; Meg's father killed them both and then killed himself. No one wanted the 10-year old girl, including the miserly cousin who finally did take her in, who then treated her like garbage.
But our little Meg is a Harlequin romance pixie dream girl! She's spunky, kind, warm hearted, and brave, despite having endured her parents' horrendous deaths and shit poured on her for years, AND of course she has simple tastes (which is great when your new husband is quite wealthy; then he knows you really love him) AND she's actually beautiful with a hot body. Natch.
Because she and Marc were unchaperoned in each other's company much too long to be proper, and because she has no place else to go, and because he's hot for her (which he can hardly admit), they marry and he whisks her back to London.
And they can't get over their stupid agreement that this is a marriage of convenience and they say horrible things to each other to hide their real feelings, blah blah blah, until the last chapter of the book.
* Another spoiler: The reader is given the impression that Marc' mother must have been unfaithful, but it seems it really wasn't the case. Instead, she died in childbirth when Marc was 15, and his father was so devastated that Marc decided he never wanted to love someone that much.
One more thing: One guy in the book is a rapist; he violently attacks Meg on her wedding night leaving her with bruises and a swollen lip. Marc interrupts the attack but then lets the guy go BECAUSE HE DOESN'T WANT IT TO EMBARRASS MEG and then the guy keeps showing up and harassing her in London. THIS WAS HORRIBLE. Why doesn't she tell him off? It takes WAY too long for that jackassery to be resolved. Ugh.