Hmm... Well if you think there's genuinely a 'spark' or mutual interest then my honest advice is to go for it because i was in the exact situation.
The key here is to establish a clear objective in the beginning;
"we're going to give this a shot, i'm interested but lets be prepared for the chance that we're just not compatible romantically we can agree to go back to normal and be happy as friends?"
Make sure you can both be mature and accept that. openness and honesty does wonders for any relationship.
Yes there's the risk that it might not work out but you wont know until you try, and I genuinely think that as long as you're both mature and respect each other then you should be able to accept it if it turns out you're better as friends and then just go back to normal ^_^ with a really solid friendship it'll be something to giggle about together in the future.
Dont listen to the people who say it'll either end in tears or blah blah blah, it doesnt have to be so melodramatic and no friendships have to be lost if you're both good friends and are mature. You never know what can happen if you never test the waters. You might very well end up with the love of your life and discover new depths to your relationship and feelings for each other.
I encourage going for it because this is actually how I found the love of my life. We were friends for years, never considered each other in a romantic way. She started to show little 'hints' that her feelings were changing and then she was just open with me and said she was interested in 'seeing' if we could be more than friends. i was hesitant because our friendship meant a lot to me i was scared of losing her as a friend if it didnt work so we had a really open conversation about it and established very early on that our objective was to just test the waters and see if we can be more, that way we could both easily accept if it didn't work out romantically and then at least we would know that we were best as friends and we wouldnt let any awkwardness come into play.
It helped that we were both very mature and open about it. The thing is, it's things like these that make life exciting and worth living. You need to take risks now and again and explore boundaries. If you're worried that it'll be awkward to see your friend in a romantic way or be intimate if you do go on a date then just know that it just takes a while to get used to be its really not a big deal and honestly isnt as awkward as you might think. if you do feel some attraction then it will only grow and you'll become closer each day until you cant even remember what it was like to just be friends.
my partner and I have been together 4 years now and our relationship is strong as ever.
Remember that feelings arent always static. Just because you never felt some way for someone before doesn't mean you wont in the future. I certainly never saw my friend in a romantic light before and now i cant even imagine what it was like not to love her.
This might seem like a weird question, but do you have any interest in astrology at all?
Yes a lot of people see it as a pseudo science, but its scary how accurate it can sometimes be. You might want to just check out you and your friend's signs compatibility online it can be fun to read about that stuff and might help in your decision process. Even if its all mumbo jumbo i think its pretty fun to look at astrology sometimes. you never know.