This. All of these things broke the rules that were in place at that time. Even 20 years ago it was not ok for
adult male leaders to be alone in the car with teenage girls
or to have secret , private , intense , exclusive friendships
or to talk about sexual matters with opposite sex kids
or to ask teens about sexual at all at all unless they asked for advice
or to use kids as unpaid babysitters and cleaners
He KNEW what he was doing was wrong and that’s why he hid it from your family members. He was clever enough to get you involved with his wife and kids as a cover.
I expect he went out of his way to let you know that he didn’t talk to other girls like this and that you were in some way special to him.
I don’t know if his motivations were sexual or not or just about boosting his ego or making his wife jealous. I don’t know if he ever would have laid a finger on you or if his interest in you was just a private fantasy.
But in a way it doesn’t matter. His actions were very inappropriate and he did exploit you for his own benefit. Im sure you are right that he told himself that he was just trying to lead you to the Lord but that doesn’t make it ok. He knew it was wrong and he went ahead and did it. He used you for his own gratification.
Its just the same as adult men who do this in other settings - the teacher who is “ helping “ with private GCSE maths or the sports coach who is giving “ extra coaching for a competition “ in a way that breaks the rules and puts kids at risk. They take good and honourable things ( working or volunteering with children and young people ) and exploit it for their own ends.
Im sorry this happened to you , it was wrong and you were not to blame in any way at all.
It’s not your fault that you didn’t understand what was going on at the time.
It not your fault that you colluded with him to hide this from your family - you were under his influence.
I understand that you feel conflicted about it now, because you are torn between how you felt at 15 ( I have this lovely kind person who is a friend to me and makes me feel special ) and what you know at 35 ( this was out of order and I was a victim , even though it didn’t feel like that at the time ).
it’s normal to feel conflicted and upset , that your warm happy memories are now in some way tainted.
All the mainstream churches and church youth organisations in the UK now have a safeguarding helplines or similar - you might want to consider phoning them up and having a conversation about what happened to you. It’s always confidential and you don’t have to give your name if you don’t want to.
It might help you feel clearer in your head about what happened . because if you are over reacting and he didn’t do anything wrong, I’m sure they will tell you.
You are not wasting their time, that’s what they are there for.