Help me determine my kitten’s gender?

I adopted Joey 4 months ago and the vet determined that he’s a boy. We never really brought up his gender afterwards during his vaccination.

He is around 6 months old now and I don’t really see his ‘scotum’ growing. Compared to the kitten nearby where I live (which is around 2 months old), his ‘male parts’ look less prominent.

I don’t have the time to visit the vet this week, so can someone help me determine his/her gender? I’m a little confused.