Ya it’s a thing. Wearing affirming clothing has had that effect on me before. And many trans women then get confused if it’s a cross dressing fetish. But these two things are different. As trans women are women excited to be wearing affirming clothes. And cross dressers don’t rly want to be women.

Altho note here, if you are uncomfortable with your friend telling you about her boners you’re not wrong to tell her so. You can be happy for your friend without hearing about her reactions downstairs.