Getting to know SO 6yr old....

Jordyn`s Mom
My boyfriend and I have been dating since 05/18/14, and we have a very good relationship, we go on dates often, we never had any big problems, or arguments. We had one recent break for about three weeks, not due to cheating or anything bad, but more because of some financial problems he was going through, but my question is... I have two little ones by someone else, but my kids have met, and know him very well, and he have a 6yr old. I have somewhat met his son twice, but it was because his son was with him at his job. I never spent time with him, and his son like to get to know him. I invite them to any event that I take my kids to. I do know that his last girlfriend, met his son, and his child's mom stop letting him see his son for about a month. But we are getting serious, and I just wanted to know, when do you all believe that I should be introduced to his son, and actually get to know him?????