Girl I will advice that you go for it now that the two of you are still single, is better for you to do it now and if he say’s NO then so be it that you will later find out that he also have the same filling for you and also he is a shame to take the NO answer.
And then may be the two of you later find different partners and then find our that the two of you fill the same way for each other then you will start been unfaithful to your partner, so Girl as for me take a step now what ever the out come is part of life experience as along as the two of you are not related is just family friend.
People will say what ever they want to say but remember that you are not in this world to make people happy but to make yourself happy.