or maybe he was referring to how jaei tried to cover up for taeha? seems like in earlier chapters, jaei would never gave excuses regarding taeha's live but now he does. maybe that's why big daddy mentioned about jaei seeing someone.
from what i got feom doing my own translations way back, its either because the pronouns in korean are confusing for mtl translation,s or the translator didnt proofread, because the korean pronoun used could be he/she/you/they.
THE EDGING IM GONNA TRHOW MYSELF INTO TRAFFIC!!!!
And now they're teasing their backstory to him liking her too IM LOSING MY MIND