Hi H.!
My sister and her wife raised 2 children together from fairly early on, one child was 3 when my sister entered the picture and the other was 5 if memory serves.
They were very honest with their children, always, and told them that they would not "out" themselves to their children's friends and families unless the kids had already done so. Their daughter didn't seem to have much of an issue with being open with her friends, most of them and their parents knew.
Their son seemed OK with the situation but had very little contact with his father, (not for lack of my sister-in-law and her son trying but for lack of the father being willing to do so). When he was 16 or 17 times got very stressful and it was obvious that their son really needed to know his father better so he moved in with him under their pressure. He had been no support to them or his son over the years at all, time was up for him to be a man and be a part of his son's life.
That was the beginning of a real transformation for their son. Instead of being angry at his mother, he finally saw why she had left his father. He lived with his father for a few years and became a man with his father. He has since moved back to the area with his girlfriend and their son. It is really neat to see the shift that has happened and to see the relationship between my sister, her wife and he blossomed into something new and even healthier.
So, part of the issue might have been due to being raised by two women, (though my sister and her wife both have some very stereotypically "straight" roles, my sister does the lawn and outside work and her wife does most of the cooking and cleaning), but the larger part probably plays in the son's relationship with his father.
If Ato is a boy, (sorry, I have never heard that name before so I am unsure... cool name, though!), then he will probably be the trickier of the two children. I, personally, would recommend hooking him up with the school counselor and/or a mentor or big brother and having him meet with the counselor, (a man might be better if that's an option), regularly to hash out any questions he may not feel comfortable asking you directly or to just talk.
The teenage years are very difficult for kids and I know a counselor helped me when I was a teen. My parents are both counselors so I knew the importance of talking through things. I asked to start seeing a counselor and it was great, it was just nice to be able speak openly and not have to worry about hurting anyone's feelings.
Males often don't need to chat quite as much about feelings etc. but it still might be a good option for your son to have someone he can confide in. It will also be important for him to understand the counselor's confidentiality so he knows that he can talk about anything, (except hurting himself or others), without worrying about it getting back to anyone else.
I hope this has helped a little. My "inner counselor", (LOL), feels that I would be remiss if I didn't note something that my parents are always mentioning though, (and if this doesn't apply to you please ignore it);
Kids need stability.
If you are in a permanent relationship, (or single and dating when the kids aren't around), that will be a BIG key to family success! The worst thing someone can do is keep moving from person to person when they have kids. Letting the kids meet the person, until the relationship is a permanent one, can be very damaging.
That abandonment issue that kids of split parents feel happens and re-happens every time another partner comes and goes. Many kids would be just as happy with one parent as they would with one parent and a step parent.
I hope this helps and doesn't sound cold or arrogant. It was not my intent and I apologize if I did at all.
Kudos to you for being true to your heart and for being receptive to other folks' opinions and input! Best wishes to you and yours. :)
S.