Another person explained what happened, so I'll tell u what they said from the raws!! SPOILERS btw
Alek raped Hen while he was unconscious and drunk, he marked him in the act. This was at an after-party, btw. Ivan was also drunk, so Alek dragged him to the room and used him too, he raped him. After the "threesome" he left Ivan and Hen in the room before they woke up. When they (Ivan and Hen) woke up, they didn't remember what had happened and Ivan assumed the mark was his doing. After this they started the relationship as we know it. Alek had intended for it to be a shit show but that didn't happen, which made him jealous. He fell in love with Hen and as you can see he's trying to abuse him AGAIN.

I- what? Someone explain something to me please!!!!
All I know is Hen is suffering
Like wtf Alek
For Ivan too I feel bad for him
SEND HELP