This was ad-libbed by the voice actor, Craig Ferguson and they chose to keep it in because they loved it. Kids won’t get it but adults will be thinking “did he just imply what I think he implied?”
And later the director confirmed it.
DeBlois revealed that, the reason Gobber never got married, is because he is homosexual. This makes him the first homosexual character of the franchise, and even DreamWorks itself.
"i am not at all physically attracted to you"
is an absolutely valid reason to not want to date someone.
People had the nerve to call me shallow for this.
By the way, it’s also totally cool to turn someone down without explaining your reasons. You are not interested, no will suffice. Do not feel pressured to explain your decisions to someone else.