Kendra Wilkinson gets cranky when she doesn't get enough sex.The former 'The Girls Next Door' star has three-year-old son, Hank Jr., with husband Hank Baskett and although the couple love being parents, they get frustrated when their son interrupts their private time. Kendra said: ''[My least favourite part of parenthood] is when Little Hank doesn't want to sleep. We get cranky if we're not having our fun time.'' However, the couple are hoping to have a sibling for Hank at some stage. Kendra explained: ''It's whenever the time is right, we're not forcing it. But you never know. Hank could always use a sibling.'' Meanwhile, although she is head over heels in love with her husband, Kendra admitted he sometimes gets on her nerves. She told Life & Style magazine: ''When he finishes my sentences, I can't stand it. It's cute but sometimes I want to finish it. Let me finish my damn sentences Hank.''