Like so many of the other replies I feel so much for you, and hope you are able to get the help and support you so desperately need. I wish you well.
I do have to say how lovely, respectful and kind your son seems. You have obviously done a brilliant,brilliant job in bringing him up.
I am the mother of 4 children now in their mid to late twenties. I am also a foster carer and therefore have been through the teenage years several dozen times. With almost everyone they began to have relationships about the age of 13. I met my husband then too, and we have now been married for 38 years. However, the age of 13 is also the age they become more private and no longer tell you everything, that's normal. As long as they know they can come to you with any problems, that is fine too. My own reaction is to welcome any friend or boyfriend/girlfriend into our home. Get to know them a little. Be interested in what they have to say and just be generally welcoming. Maybe when you go out for the day as a family, ask the girlfriend
along too. Things like that.
As for the "roaming the streets" - well they aren't pleasant words really, but in reality that's what teenagers do. They hang about with their friends in town and around the shops, or in our case as we live in a seaside resport, hang about on the beach together. It's just the norm. I have also found it the norm for them to go to school early, come back a little later so they can be socialble with their friends after a day studying. I think it can be very difficult for the young person if you do not allow that at all. I do understand that part and some of my children have autism and learning difficulties, and obviously need a little more supervision than others of their age. That's why I have found it important to welcome their girl or boyfriends into our home.
I did want to say two things though. From about the age of 13 they tend to become complete misery guts on any family holidays. I think I have found that with them all. However, I have also found that in their very late teens, early twenties, they suddenly want to come again!! So I am sure one day your son will remember those lovely family holidays and want to experience them again. Mine all have,
But the thing that most worries me is when you said:
If im totally honest i dont want a mature sexually active man in my house
It concerns me because in a few years this will happen to most young people. I guess none of us like that thought of it - not even though my daughter is happily married with children of her own now! But it is something that is normal, and once again being open and honest and be willing to chat and listen and answer questions is the best way forward. I hope that you can get the help you need so you are able to do this.
But if you really do not want a sexually active man in your house then either your son does not become sexually active and hence misses out on the opportunity for an ordinary, loving relationship with the partner of their choice. Or he withdraws from you emotionally, is not open with you, keeps secrets ,maybe leaves home earlier than you would wish, just so he can can experience "normal" relationships which include being sexally active elsewhere. I am not really sure which option is worse, neither are good options. But as you have a while before this naturally happens, and it does happen for the vast majority of late teeens, hopefully you will have found the right support or therapy for your sake so you can feel better about things and be there for your children as they become young adults.
Also I think you said about no longer worried about his education because he will go off with some girl (or boy). Well, yes hopefully he will develop a loving relationship and find the person he wants to be with - that's just part of being a human being. But you can have an education AND a relationship, it isn't one or the other. I think when my children were mid teens that's what a wished for them - to achieve what they could educationally, have the opportunity to enter a job they enjoyed AND found the person they wanted to share their life with. As I said I met my future husband at 13 and knew from the second we met we would spend the rest of our lives with...but I still got a great education and achieved well academically.
However, I must say your son seems lovely. Some of the children I have seen through these teenage years were awful. Yet they do come our the other side. Your son however with your support sounds such a respectful young man, and that's all due to you. You should congratulate yourself for that!!
I really, really wish you and your son well xx