I try really hard not to just outright contradict canon because I know that fandom can get very echo-chambery very quickly and the way to head that off is to at least TRY to ground my interpretations in canon but like. Forgive me for saying so but #myIlya would never do that whole 'You can sleep with other guys if you want' thing. I just cannot imagine him having that whole We Don't Own Each Other thing going on. We KNOW that Shane is jealous and it is low-key sort of used to villianize him a bit in TLG but I NEED you guys to understand that in the world I'm living in, Ilya is right there with him. Ilya found out about LA Blowjob and Mexico Top and he wanted to bite through fucking concrete. Ilya absolutely believes in ownership over a partner because Shane is FUCKING HIS.
Like. In the theatre of my mind that whole 'Do you want to sleep with other people' miscommunication goes completely different and Shane aims low and says some shit like "How would you feel if there were pictures of me with my tongue down some other guy's throat," because Ilya complains ENOUGH about the still-Googleable pictures of Shane and Rose and they never did anything less chaste than a peck in front of the paparazzi and, crucially, Shane was not even ATTRACTED to Rose. And Ilya considers this for a minute, the idea that not only might someone ever touch Shane the way that he does but that there would be evidence of it--and then he doesn't know what happens to his face but Shane's eyes blow wide, pupils enormous, and he looks like a prey animal that can't wait to be caught.
"Sorry," Shane says, "I didn't mean that--"
But Ilya is already darting out a hand. He presses his fingers hard into Shane's chin, pulling his face up, and says, "Remind me who you belong to."
And Shane shudders and says, "You."
"Who touches you right? Who knows just how to fuck you?"
"Remind me, kotik, how many people have made you scream their name?"
Shane opens his mouth and has to press against Ilya's thumb on his tongue just to say, "Only you."
And yeah it's a double standard, because Ilya does have a body count in the triple digits and there IS evidence of that on the first-page image results of any search for Ilya Rozanov, but it's a double standard they both get off on because Ilya gets to put Shane on his knees and tell him that he was made to take Ilya's cock, that his hungry hole and slutty mouth will never, ever know another dick that isn't Ilya's. And Shane gets to look up with Ilya's cum on his chin and lips and say, "Tell me I'm the best, tell me I'm your favorite, tell me that none of the others ever fucking gave it up to you like I can."
Which is all true, of course, but that doesn't stop Ilya from making Shane prove it.