I'm not sure I would call it "oppression", but it's clearly true that heterosexual men are by far the MOST controlled by restrictive gender norms. It is straight men who are most intensely shoehorned into this concept of "masculinity" that may or may not suit them, and their status is severely downgraded if they deviate in any way.

If you doubt this, imagine a straight man wearing eye shadow and a mini-skirt. Compare to a straight woman wearing a tuxedo.

See the difference?