Responses
I'm pretty sure he didn't sleep with anyone else because in the previous chapter they talk about how he didn't realize they'd bonded because he'd never stopped thinking of Taeseo and had a poor sense of smell. If he'd tried to sleep with someone else it wouldn't have worked, but he didn't even try is how I read that.

Okay wait a sec so was the ml of other couple fucking around those 4 yrs ??? Can someone tell me ?? He asked mc about being chaste and all so was he sleeping around ??? If he was im gonna lose it now