Statutory rape evidently.
In Islam, there is a presumption that if a male and female are alone together for sufficient time which is defined (IIRC between 20 minutes and an hour) sex has occurred, and in Islam the sense that sex makes a marriage is much stronger than it has been in the west for centuries.
Islam is neither entirely wrong on these points, nor entirely correct (especially on the last one).
In the words of Pope Francis “Who am I to judge?”
Thankfully, Pope Leo looks to be the sort of person who is likely to read fully and then express himself concisely, and so may recall the answer to Pope Francis’ question anticipated by Monte Python “I’m the Bloody Pope I am”.
Having now read the article, given the culture in which it occurred, I would sentence him to 5-15 years at least if there was a threesome, and sentence the person involved in the threesome to the same.
In another culture, allowing the girl’s kin making him a triple amputee might be appropriate.
The alcohol, with hints of date-rate drugs, makes it something beyond statutory rape and threesomes are unnatural.
That he said to keep things under wraps until 18 points to his intentions being perhaps not entirely dishonorable, but mostly dishonorable at best.