Tainted Blood - Marquis de Sade, Vampire, #4

"The Hughes were dead and resided in a contemporary four-bedroom house with hardwood floors and granite-top kitchen counters." The family of five are vampires. Mom, who remembers the 18th century well, loves to dress in the clothing of that era. Dad is a traveling salesman who tries to be away from home as much as possible so that he may engage in typical vampiric delights. Vanessa is bored with childhood, Roger wishes he were normal, and Chuckie, the toddler, can out-curse the most jaded truck driver.
But nothing seriously outrageous occurs in their lives until Aunt Marie and Uncle Sade come for a visit.