To be honest, I wonder if this is really worth debating, because we shall probably never know, for certain, what was going on on Leonardo's mind and what was influencing him.

However, the item has been posted for discussion, and I find it quite interesting to discuss.

As for effeminate-looking young boys, there is no need to try to convince me, personally, because I know that this is so.

On the other hand, young women also looked 'effeminate'.

Here are some very pretty young boys by Raffaelo & Perugino:

I fully accept that Leonardo might well have taken a moment from the biblical 'Last Supper', with Jesus and his twelve male disciples, and painted it exactly as per the Bible story.

Like others, he may well have decided that the 'beloved disciple' referred to John, and then made him look like an effeminate young boy.

On the other hand, some people ~ rightly or wrongly ~ have interpreted Leonardo as something of a rebel, who had problems with church dogma.

He was also very clever.

Heretical ideas were flowing around Renaissance Florence.
A number of Renaissance paintings are known to contain symbolism and, perhaps, 'hidden messages'.

If Leonardo had heard some of the heretical stories, and wanted to include them in his paintings, then he would have been intelligent & talented enough to include them, secretly.

He may not have done ~ but it isn't impossible.

Can we see anything that makes us wonder, when we look at Leonardo's 'Last Supper'?

Well, certainly some people can.

They wonder why the boy who is supposed to be sitting in the lap of Jesus is leaning away from him.

They wonder why Leonardo left that noticeable 'V' shape between them.

They wonder why John looks so much like some of Leonardo's female models.

For my part, it is not that I do not see or understand the arguments, it's that I do not think that anyone can conclusively know what was in Leonardo's mind.

Furthermore, I think that it is worth looking into other possibilities ~ and other mysteries.

Berzelmayr has posted Raffaello's 'St Sebastian' (I hope there won't be copyright problems with that ~ or with the images I shall include).
Here are some more people by Raffaello, who look just like St Sebastian ~ and like each other:

One is Mary Magdalene at the Crucifixion and one St John.
They could be twins! (Or triplets with Sebastian.)

Here are Mary Magdalene and St John at the Crucifion, again ~ by Perugino this time:

Twins again!

You can see the full paintings here:

I cannot tell the difference between Mary Magdalene and St John in these two paintings.
Why should that be?
Why were they painted as twins?

Maybe, if I could understand that, then I would be better able to understand why Leonaerdo painted his St John looking exactly like another Mary ~ the mother of Jesus.

I feel that, if the paintings, themselves, didn't pose the questions, then nobody would be asking them.

That doesn't mean, of course, that there aren't perfectly reasonable and non-controversial answers to these questions. smile

"The secret of success is constancy to purpose" - Benjamin Disraeli.