UNHOLY MATRIMONYIf Kaitlin O'Herlihy got one more wedding invitation, she was going to scream. Suddenly everyone--including her grandmother--was getting married. It was making a shambles of her well-ordered existence. It had also brought a certain Brendan O'Herlihy back into her life, as the best man. That troublesome ex-husband of hers seemed to be everywhere, making a perfect nuisance of himself. He was as maddening and exciting as ever, and she could certainly do without any pesky reminders that he might be the best man for her.