Vanillx

I'm trying to find a manhwa, it's a fantasy/action and romance one. The mc is a girl and she got transported to another world where the "God"/Queen (has red hair and dress iirc) wants her dead to keep her position. Mc and her is related to each other (mc lost her memories when she was in that world and kinda reincarnated to earth i think). The big gem that is the source of the queen's power is resonating with the mc like she's the original owner, and if the mc is alive then the queen will lose her place to her. The ml saved the mc from the queen's palace when she first got to that world and is helping her trying to restore her memories and her power. Ml knew mc from before because she saved him as a kid, befors she reincarnated/moved to earth. I think when mc reincarnated to earth she was being kept as a test subject or something

It's a straight smut manhwa, the mc is a girl with glasses and short hair (iirc) and the ml is pretty and sub. They're in college and the mc is kinda inexperienced at first and is learning(?) Or exploring stuff with the guy. Last chapter i read was the ml and his ex were getting on it, kinda like teaching mc abt stuff and the mc was watching them (again iirc)