Regency novel..rake hero marries older, plain sister with rose tattoo on her breast

Can't remember when I first read this book but it is an older one by a famous author. Plot: Hero is needing money, responds to summons to the house of man whose younger daughter (a loose woman), a beauty, was once his lover. The father suggests he marry the older plain daughter who went with her sister overseas and returned with a son (turns out she is only the aunt) and a bad reputation and a rose tattoo on her breast. He does marry the woman since he is needing the money and eventually falls in love with her and finds out she is raising his son