You've hit the nail on the head - it always comes back to prejudice and victim blaming.
I've lost count of the number of times I've seen people questioning why, if Stuart really was straight, would he go to a party at a gay man's house and it riles me up every time!
I honestly believe he was starstruck and, I think he, in common with two of the young women who were also there that night, by their own admission, wanted to see Barrymore's house to "see how the other half live". Barrymore was rich and famous, he lived in a large, gated property with a swimming pool while Stuart Lubbock was a factory worker from a council estate. It would have felt like another world to him, not to mention how he could show off about having been there and being on good terms with a such a well-known celebrity.
I also think Stuart was drunk, he had taken Ecstasy, he was having a good time and he was keen for the night out to continue. It was a gathering of six men and three women and, to my knowledge, only two of those men were openly gay and I really don't think the sexual orientation of any of the guests was at the forefront of Stuart's mind when he agreed to join them.
However, even if he had been gay or bisexual or was simply wanting to experiment, that did not mean he in any way deserved his fate like some people seem to suggest.
And equally, just because Barrymore was gay, it didn't mean that any man should have naturally feared him and his lifestyle.
The way this case was initially handled and reported upon was atrocious and personally I don't care if Stuart Lubbock actively went to that house for sex, he did not deserve to be violated and killed and then his death be covered up so that his family still don't have answers 20 years later.