The way I see Yaeji, her love language is definitely physical touch and sex... Lots of it.
She doesn't hesitate to engage in PDA, even when her relationship with Minjae is new. She doesn't hesitate to lean on him, cuddle or just let him hold her when he's feeling clingy. And of course the copious amount of sex they have and the new things they try out. Compared to Minjae who's love language is more on acts of service. He dotes on her, does alot of physical labor (like carrying her stuff or student council stuff) and sexual favours.
There are other subtle things like her talking to her friends about him, heck recently she introduced him to her closest friends and eating lunch together with her coworkers. She respects him and their relationship. Not once she had ever thoughts or entertained the idea of getting back with her ex/TA when he was being creepy and disrespectful. She even drew boundaries, which still gets violated by the ex and by strangers who aren't even in her circle.
Her main priority is her studies, her scholarship, her library job and her duties as a student council president. All that while in the middle of being in a love triangle "scandal". It's kind of understandable why she would be angry and disappointed if her partner would be immature and incite fights because of jealousy. She worked her ass off for 2 years to financially support her family and now has the opportunity to finish her education. She's got no time for that nonsense!!!
While I can see that she isn't perfect ( good lord I hate that her conflict resolution was to immediately fuck it out) and her communication with Minjae needs a LOT of work, but you can see her opening up more to him. She might not be 100% in love with Minjae just yet but the fondness and affection is there. And since this manhwa is still ongoing, we will definitely see them grow closer and grow as characters.
All that being said, it's definitely sad to see how much hate she is getting in the comments. She's such a nuanced character. If she was a man and this was a BL or if she and Minjae switched genders,,, y'all would be eating this manhwa up.
NGL even though this was mostly a p0rnhwa,I just kind of wish all three had better communication especially in terms of what it would be like to be in a polyam.
So this is a poly right? Im in the mood of a poly ending hahahah