There's no reason to return the suit.

"I'm a 29 year old gay guy"
Why does this even matter?

Its not a stupid question. He starts his letter by clarifying that he is gay, then follows with a predicament that has absolutely nothing to do with sexual orientation. Just thought it was weird and unnessasary.

Questions that you already know the answer to are stupid questions. And you just pointed out that you already know the answer to your question: it doesn't matter. Suck it up and show some grace.