Went and bought this game since no one had seemingly bought and posted it here. I can't promise a fast upload speed, but I hope someone can eventually help out with that.

Title: レズ姉に男を教えてやりました ～彼女は姉に寝取られていました～ / Lez Ane ni Otoko o Oshiete Yarimashita ~Kanojo wa Ane ni Netorareteimashita~

https://vndb.org/v51144
https://www.dlsite.com/pro/work/=/product_id/VJ01002474.html