i think its because for woowon, sex is how he can be the closest and most intimate with seo-an. he’s so obsessed since that’s how he ‘s learned to cope with his loneliness. also, they were heavy in the honeymoon phase when all of it happened, so woowon may think this is the most “love” he can recieve and reciprocate
and seo-an also doesnt have a healthy view of sex :/ he sees this as a way for woowon to rely entirely on him, which is what he’s wanted all along, that’s why he just… lets it happen. he’s also very dependent on affection and his own mental troubles aren’t gone. not that it excuses woowon— he absolutely needs help (and maybe some time away from seo-an), but i think it does fit in the context of the story
i really don t like how author is making woowons forcing himself on seon. woowon obviously has ptsd after what he has been through but he never was sexually insulted and all he does is basically forcing himself on seoans, who wont tell a word because he loves ww sm + we want to be the one who helps him this time. but it really makes me sick like those authors dont know how to continue the plot so they always end up with sexual abuse.