Being caring and romantic is one thing but if his clinging is from insecurity then that is quite another. Insecure men tend to be abusive and demanding as time goes on.

If you decide to meet him having his nieces there is a good thing. Make
your initial meeting the type that would be of a short duration such as
coffee at Starbucks. If all is ok on this initial meeting then you can plan a
meeting of a longer duration.

You should tread carefully, It is one thing to date someone with a handicap that they handle well and another to becoming a crutch that they need to have around.