Adults making jokes referencing sex displays the same immaturity as children making jokes referencing poop.
Though I'd rather not laugh about them, there are certain jokes that reference sex that are, admittedly, witty and well thought-out. However, the bulk of jokes referencing sex are initiated by the train of thought, "I can make this vaguely about sex and then it will be funny!"
It's not funny. The word "sex" is not a free ticket to humor. So don't roll your eyes at children who make a joke implying "you just pooped!" if you make jokes implying "you must have just had sex" (or something of the sort).
It's tactless, thoughtless, and straight up cheap and ineffective humor.
