It's a fact that gay men often lead a promiscuous lifestyle, but as with all people, there is every shade of personality and behaviour in evidence, so stereotyping should be avoided.
Because as a rule, heterosexual couples have children, they lose the 'single' lifestyle they enjoyed growing up, and when first together, but gay people never lose that lifestyle, so the opportunities for sexual freedom are far more eveident for far longer.
To answer your question - the media love the frisson of something seedy going on, heightened by their prurient attitude to homosexuality, so the fact that a friend may have come back for coffee can soon by whipped into a dog-andpony show by the papers, because a large section of soceity loves to believe it must be true.
The only people who know what has occured are the peoploe who were there, and the doctors who have completed th post mortem -everything else is speculation - and we all know where that leads ...