Let's just say it's for "adult themes." Considering House of Mirth is full of seduction games, you'd think that there would be some talk of sex. But this is the tail end of the Victorian era, which means talking about furniture legs was still uncouth. Even the phrase "make love" just means "talk about being in love." It's particularly odd that Lily's fall from social grace is largely due to rumors of her affairs with married men – first Gus Trenor and second George Dorset – since she never allows so much as a wandering eye.