Sasha-chan to Classmate Otaku-kun - Vol. 1 Ch. 7 - Your Wild Fantasies

[MangaDex]

 

[Trostishere]

Sensei was hit by a confusion spell

 

[Dekisugeh]

Boner in class, very relatable, but instead of a cute russian girl causing it, its my class's air con

 

[henman]

One of the dumbest things I've seen in a manga. Good trash. Nice to read it again

 

[Mangamoz]

Aw, she must have had a nice hit of nostalgia reading his homemade hentai doujin.

 

[gronkle]

My boy needs to learn the "belt tuck method" of erection concealment. Saved me from embarrassment a few times back in the ancient times when I was a teenager.

 

[yamiyugi101]

I legit wonder what the school would do to him if he popped a boner in class like what's the standard punishment for that

 

[Kierlak]

I legit wonder what the school would do to him if he popped a boner in class like what's the standard punishment for that

You have to write 7 porn doujins for the official local female Russian transfer student per infraction.

 

[StuffedP]

huh
just read the doujinshi

 

[Anon94]

Sensei truly must pack a big Iron if it can be distinguished through his pants by others in plain sight

 

[xXPenisXx]

How tight are those uniform pants gotdamn
Unless he's really hanging dong like that that should not happen

 

[Raydnt]

She returned it THE NEXT DAY??
Yall know what she did with it

 

[booterror]

She returned it THE NEXT DAY??
Yall know what she did with it

Why does it smell faintly of sushi?

 

[Cyromantik]

I legit wonder what the school would do to him if he popped a boner in class like what's the standard punishment for that

AFAIK there isn't one. Teachers just pretend not to see it, usually the kid goes through enough embarrassment from their peers.

 

[Kutabarie]

Gotta be one of the only times i've actually seen a male character pop a boner in manga. Manga MCs are usually dickless, so no matter how much tits or butts they touch they never get a boner.

 

[thereallegend123]

How tight are those uniform pants gotdamn
Unless he's really hanging dong like that that should not happen

As a former male middle schooler, I can tell you that boners could be seen in normal pants.

 

[Koraeli]

As a former male middle schooler, I can tell you that boners could be seen in normal pants.

As someone who's seen a few boners in my time, it depends mainly on angle, size, and shape.
Overall, they tend to stand out the most if they're just a little below average; if they're too big, it's pretty hard for them to even reach a position where they can become visible unless you're wearing really thin or loose pants. And of course if they're small enough, they won't be very visible anyways.
Ones that are straight or have an upward curve will be a lot more visible than ones with a downward curve.
Then the natural angle varies; some will never under any circumstances point straight forward or up on their own, either because they're too heavy for that (or too front-heavy, with the base being narrower) when erect, or they just naturally point downwards more. So that makes it harder for them to be visible beneath pants. Smaller ones are again more likely to stand out because of this.

But really, when I was in school I never even heard of anyone having a visible boner (and it's the sort of thing that would be talked about), let alone seen it myself. To me, it's always seemed like something that's only common on TV and in anime/manga, but very rare in real life. Maybe all the boys around me were just really skilled at hiding it, but I'd guess it's just not a problem at all for most people.
Swimsuits are a different story though, a whole lot of obvious boners at the beach or pool.