Well, I think it should be soon as y'all decide ur ready, but in my case ialready new my bfs mom b4 we started dating an he new my mom and dad so all the same no akward situation for me
It is best if you wait awhile before you introduce your bf / gf to your parents because this gives you time to make sure if it is going to work out or not, don't want to introduce him/her a weak in and then break up a weak later. I usually wait a month.