Most Helpful Guy
It's perfectly fine to ask a guy out, and there's just way too much pressure on guys to do it in fear of rejection. However what you should do is make the first move and give an indication of your interest in him. Just send a casual text for coffee or a drink, to break the ice.
However, I'm slightly ol school so if he accepts your invitation and you have a good time suggest we should do it again and let him then ask you next time... if he does not oblige you have your answer and little damage is done, bearing in mind your family friends status.