maybe 15/16 cus he looks so young
Prolly 18 and above, he is an omega and omega often look younger than their actual age
They said he didn't reach sexual maturity...so he was probably between 12 to 14 since sexual maturity usually means the ability to impregnate or get pregnant.
If that was his age when he was found then he is an adult right now since there were years of time skips
how old was the omega when the dude found him??