
Yo they didn't out right say it, and I don't think seme did sleep with the ex cuz his only motive was to get with mc through the ex but seme did make it seem like ex didn't sleep with him coz his dick big but I think that was staged the way seme is swoon for mc I can't believe he slept with anyone at all. He also said he gave his virginity to mc so I'm concluding he didn't ever.

they never went out. Myojin said that there was no on else but Yijo (ch. 20). He gave the ex his number because he didn’t want to lose contact with Yijo (since Yijo disappeared for a year due to the military). And after those two broke up, he allowed the ex to post his picture because he thought that was the only way to meet Yijo and give him an impression (since Yijo always forgets their encounters). I’m positive the ex delayed their breakup because he was trying to woo Myojin at the same time (scum of the earth (╬ ̄皿 ̄)凸 ). The ex met up with Yijo and recorded the message because he knew Myojin likes Yijo and assumed Myojin stopped contacting him because those two finally dated. The ex wanted to break up the two by gaslighting Yijo and provoking Myojin into contacting him (ex) … but since those two never dated, the ex ended up ruining his own plan (scum of the earth x2 (╬ ̄皿 ̄)凸). Hope this clears up the confusion.
Is the seme really slept with the ex?
Or he was just pretending to be the ex's new lover??