beta
The love interest said he hates omegas. With the mcs timid and cowardly personality, his reaction checks out.
Since the omegaverse talks about gender dynamics, irl doesn't this equate with the love interest saying he hates a certain lgbtqa+ gender?
So, with that context, it makes sense why the mc is extremely hesitant to divulge his secondary gender because he's not just at risk of losing the affection of the person he likes but also having an important, unchangeable piece of him get hugely rejected by someone he deeply cares for. Also, add in the fact that he might get bullied for it (not necessarily by the love interest since we know he cares for him)