What was Hikaru doing to Yoshiki in episode 3?

I’m really invested in the anime and me and my boyfriend have just watched the newest episode. In the classroom scene where Hikaru half transforms into his monster form and gets ontop of Yoshiki, what exactly is he doing? Is it supposed to be a kiss? Or something else? Or is he trying to enter Yoshikis body? Was he trying to manipulate something inside of him? I’m genuinely curious and don’t want to make any wrong assumptions. I felt kind of uncomfortable as whatever it was seemed kind of done without consent and thus am pretty conflicted on what it was supposed to represent.