100%. It’s funny you mention that, as that was the situation with my first partner/wife. We ended up being close friends for a few years and I didn’t take my shot because I didn’t want to ruin the relationship, but thankfully one of her friends pushed the two of us together and we’ve been happily married for years.
My situation is also funny because I did a similar thing with my 2nd partner/our girlfriend. Though thankfully she was confident enough to make the first move, I wasn’t going to risk the friendship even though I knew we were all poly. But in either case, it was always friends first, then light flirting that only increases as it was reciprocated.