I think it's pretty obvious here they're not siblings or have a sibling relationship. Besides the terms used, they met at an older age, and are not related. I guess the only issue is the marriage between the parents. Although by the standards of the XVIII century, makes sense to make your successor marry your daughter. He will have a stronger claim to the position and all. Although if you know anything about (I think) Renaissance Italian noble families you will get it no problem. That was quite the drama.
Right. They parents are married!!!! So yes they are half siblings. Wtfffffff
Honestly you're right, I just read so much fucked up shit, in both hetero and yaoi section, that I was just relieved they weren't actually related, the age gap isn't over 10 years and there is no rape. Looks good ٩(`･ω･´)و
This is so fucking weird, you mean to tell me you guy are adopted siblings but they wanna marry each other?? Tf??? that’s incest in my eyes I’m sorry. If you grew up together with someone - and have a psychological sibling relationship yall are sister and bro basically like why they gotta make it gross man