The truth is, no-one truly knows what that lad RIP was going through only that he took his life. This photo is just another indignity. What I've seen from posts is that this man in life was the life and soul. He's featured in videos grabbing his groin and generally larking around happily like young folk do in the moment, especially if they've had a couple of drinks and are having a good time. It certainly doesn't point to their sexual orientation etc or mean there was a relationship there between them.
In one video mentioned above, they are with Adelle and others, both he and marcus are wearing the same clothing as in this photo, with the same background. It's probably safe to say the picture was taken on the same day as the video when a group of them were having a good time, in summer with a few drinks perhaps? Again, that doesn't mean anything happened between them other than larking about or that it's OK at any point to insinuate a relationship. To put this post up really is disrespectful to his memory and his family and friends. The man can't put forward his side to this.
What we do know more of however is Marcus's background and behaviour. How he is known to become obsessed with men, how he had become obsessed with this man, and how this man had warned him away from turning up at his home uninvited, and more so how he's been capitalising on this man's passing for likes and Social media engagement. This may well just be a photo taken while a group of them were larking about and marcus has misinterpreted the situation as 'love' as he puts it. If he's any respect he'll delete it from insta & Facebook.