I get that ppl are worried about Femc falling for the dad, but tbh I just don't get that vibe, she's clearly only worried about him being experienced in xoxo when she's not. She's just too attached to yeon-ho whole being and worried about his relationship with his dad, and of couse she'll be ashamed to be caught in awkward situation. Her last comment sounded objectively valid in my opinion. She didn't side with his dad or with Yeon-ho himself. Neutral stance is best stance.
To be fair, I would also feel awkward after doing xoxo and then saw my partner's photo ok.... And i feel that it's shown she was staring at the dad's photo at ch 37 for panel transition purpose lol