Can you truly have pure and close friendships with the opposite gender(even after marriage?)

I’m talking about close or best friends that have never committed adultery, or had romantic feelings for one another, how has the dynamic affect your marriage, I never really had a friend of the opposite gender and I am lowkey thinking of trying it out if the chance comes, however, I first want to know how they work and if they can truly remain innocent, there are many sides to the coin, please tell me the pros and cons, advice, and most importantly experience.