I honestly think that it doesn't matter if Snake is gay or straight.
If you ship Fluffyvenom, go right ahead, even if it isn't canon.
But just because Snake likes a girl, doesn't mean you can be rude about it. He is allowed to like a girl if he likes a girl !
Someone once said, "I am allowed to feel what I feel."
And yes, I am sad not many characters in animated movies are part of the LGBTQ+ community.
But it's ok to be straight just as much as it is to be gay.
(Also, he might be bisexual. WE DON'T KNOW!)
I just believe that it's completely ok that Snake likes a girl.
I respect those that like Fluffyvenom and I hope that you can respect Doomsnake.
Respect for the LGBTQ+ community
And respect for straight allies.