Nonchatte Vampiyan has a long cfnm scene:

[Jecone]

The ending of episode 1 and the entire episode 2 of this absurdist anime cartoon has a boy naked in presence of a girl. There is also a comedic scebe where she grabs his penis. Not once but twice. However, this is not exactly ENM (Embarrassed naked male) because the boy did not look Embarrassed but he definitely was naked in presence of a girl of his same age.

Here's the link:
Episode 1( it's in the ending): https://youtu.be/3TAF7gZFOco?si=JC0oQQY2Yfzr6bBf
Episode 2: https://youtu.be/ZCKg4HJ_QdM?si=MuQ4l8aOyocVWvqI

Almost for the entire episode 2. Anyways, if you guys know about any other cartoons with such scenes please make sure to share.