The Time Machine answers the question we've all been asking ourselves: Is there sex in the future? The answer is a disappointing "not really." The Time Traveller does interrupt two Eloi flirting, although in the future this consists of the male Eloi chasing the female, "flinging flowers at her as he ran" (5.34).
Now, all the movie versions of this book depict a romantic relationship between the Time Traveller and Weena, but in the book their relationship is at most a childlike sort of puppy-love. They pass each other flowers and kiss each others' hands like children (5.23). So there may not be any sex in the future, but there is affection.