A lot depends on the age of the youngest person really....if the youngest is 60 and the eldest in their nineties they are both old enough to know their own minds.....if the youngest is 16 and the oldest fifties it's not really exceptable either...
Better to ask, how young does a person have to be before it is disgusting?
I'd say that sex is meant for ADULTS only. Sorry. It is how I have always felt. And I am not changing because any open-mindedness on this subject has always lent to disaster.
There is not one reason on the planet not to WAIT. There is no reason why sex must be had. It is not food. It is dangerous both emotionally and physically to those who are not ready to explore being open to another human being and what it can bring.
As long as we are talking about adults as in 20 and up. Doubling age is getting weird. More than double is gross. A 50 and 30 is not bad but a 20something and a 50 is weird.
I heard someone say once that the generally accepted is to 1/2 the age of the older and +5yrs.
So: 50/2+5=30 40/2+5=25 65/2+5=37
Sounded good to me. Children are always off limits. Disgusting.
As long as the parties are all adults it's none of anybody's business who loves who. If a couple falls out of the range of some stupid formula that someone invented then the person who's judgmental about someone else's relationship is the one with a problem, not the couple.