>>82765497
well going to an anime con itself is a pretty close enviroment for siblings. Those cons are sexual and horny as fuck. I can tell you from experience, if there are 2 types of cons that you dont take a sibling to (a regular sibling that you are not sexually or romantically interested in i mean of course), but a partner or a FWB, its anime cons and furry cons
So i think you wanting to advance with her and she being open to it is very possible if you guys are already close enough to go to a con like this. I dont have a sister, only an older brother, and im not gay, but even he wouldnt go to an anime con to me because its too much, same for my 2 girl cousins. If i asked them to go to an anime con or a furry con with me, they would probably think i want to get them away, high or drunk, and fuck them.
When it comes to advancing the personal relationship, i think just being the perfect guy in her eyes is how you show her that you indeed are one, but then again i could be talking out of my ass here. Every girl i was with so far, i honestly picked up my sheer luck. I do not think my pick up methods work at all, i just lucked out repeatedly

I would honestly say if you want advices or help, ask Nomi over here. She is a sweet little sister who wants to be big brothers wife, and you are on the other end, so i think she could probably tell you some useful info. Another person to ask would be brosis over here, but she kinda comes and goes randomly, but my favourite swedish girl will probably be here soon