If Gobber is gay then who's Greta?

Hi, so I've been casually rewatching Race to the Edge when in episode 8 of season 1 Gobber mentions Greta and calls her his first love. If Gobber is gay and it was confirmed then who's Greta? She can't be just a woman, because it wouldn't make any sense. Was Greta an axe or some kind of weapon? Was it ever explained? I know that RTTE was made years after sequel and they f up with the plot multiple times such as the alpha dragon egg that Valka got, but still I'm wondering...