An Erotic Art connection would connect a few of your unconnected sites

Konrak
Khajuraho Group of Monuments
Buddhist Monuments at Sanchi
Pattadakal
Hampi

Although these are all Indian religious buildings we can definitely include

Pompeii

to make the connection intercontinental and secular!

There is a carving of a man and a very happy donkey in Patan also (I might even have a photo of it somewhere) - and a number of other erotic depictions!

Depends if we are drawing a difference between Erotic and Phalic but there is a rather large phallus in Tarraco

Another fine definitional problem you have got us into....!
Are "busty" Apsaras in Angkor Wat "erotic" and what about naked bathers in Quseir Amra (or even, dare one suggest it, the statue of David in Florence!)? It depends what "turns one on" I suppose. Should our definition of "erotic" emphasise the depiction's intention or its activity? My inclination is to emphasise the activity since the intention depends too much on what is regarded as erotic in the receiving culture. So that would allow in the bordello scenes in Pompeii, the Hindu depictions and (possibly??) any Phallic depictions - but presumably not simply Hindu Lingams? We must require a degree of realism in the depiction of the member surely, otherwise it is just a representation of "fertility"!

I feel like our one-time censor the Lord Chancellor who used to require a ruler and a set square to help determine whether something was pornographic or not!!

As usual Solivagant deep thinking is getting me in trouble with my boss!

Solivagant's definition seems to be approaching "pornographic" rather "erotic" - but there is something uncomfortable about classifying the Indian images as pornographic. Perhaps "sexual art" is the best definition but this sound too clinical. Whatever the name I think the art should be "overtly sexual" this excludes a lingam, but probably not the phallus in Tarraco.

Sorry perhaps I shouldn't have brought the word "pornographic" into it and i certainly wasn't trying to move our definition towards it - rather the opposite. I hasten to say that I am no expert (!!) but, in my understanding it, like the word "erotic", it is a cultural construct and my intention in trying to arrive at a definition for our purposes was to avoid the need to make such a judgement. I merely cited the "Lord Chancellor's problem" to highlight our own! We ought to be able to define on purely practical/objective matters (as the LC tried to do with his ruler!). We cannot know exactly the intentions of some of the art we are considering (though that at Pompeii is pretty clear and I have always had suspicions about Rubens and all his naked Cherubs!) and the line between celebrating potency and fertility on the one hand and inducing "libidinous thoughts" on the other has no doubt always been a very unclear one. Quite where the hindu "Kama sutra" type carvings sit ...?
A nice difficult case (I almost wrote "hard case"!) is that of the "Phallic" representations outside the homes of the Bettamaribe in Kouttamakou. Certainly they are not very realistic but their inspiration is quite clear - would you expect to see them in this Connection?

No aplogies are necessary Solivagant - pornographic is probably a more precise definition of what I meant than erotic and, according to most definitions, less culturally dependent. I was suggesting "pronographic" to distinguish between "the activity and the intention" that you mention. The trouble I get with my boss is over the amount of time required to investigate the issues you raise!

I was in Togo in 1999 but I can't immediately remember the phalli (phalluses) which probably means they were not that erotic, I can remember Bambara phallic shrines and these fall out of my definition of erotic.

Rubens was very probably functionally and I think intentionally erotic - but the stylized representations make this sort of representation fall out of the scope of my suggestion. I needs to be more overtly sexual.

I have never found a satisfying answer to the function of the images on Indian religious buildings but they are definitely overtly sexual and fall into my suggestion!