Before anyone inquires, I am not in any way telling her what to do, because it is simply her decision and I have no control over that. I just stated my own opinion as to what I think.

So my (17F) best friend (18F) have always been super close and don't know what we would do without each other. She has always had somewhat of an interesting dating history. She got out of a 4 year relationship with a guy a year ago since he was extremely toxic. Over the next few months she went on numerous dates but none worked out. She then came out to me as bisexual and started dating another girl, although they broke up after a month. However they got back together but then broke up again shortly after, and till this day she still likes her despite always complaining about her to me. Recently she just got out of a situation-ship with a guy, who she kept giving second chances to even though he was negatively impacting her mental health.

However something she told me recently made me really concerned for her. So she is apart of a theatre group that involves mostly adults and I know that she is fairly close with this guy (39M). I never thought much of it because it just seemed like a friendship. Recently she told me that the guy broke up with his girlfriend and had actually confessed to liking my best friend. She said she thinks she likes him as well, but wants give it some time before committing. She is also fairly worried about her parent's approval.

I've met the guy before and he seems like a genuine person and I've also seen how close they are. However this whole situation just feels so wrong and I know she is usually quite impulsive when it comes to relationships, and I will say I'm concerned for her because of how big the age gap it. It's also down to maturity levels because, well he's 39, and my best friend just turned 18 last month. I don't know but the whole thing just seems really creepy. I just told her as long as she's happy, I'm happy but that I don't think it's a good idea. She got pretty annoyed at me and hasn't spoken to me since.

I understand that it is her decision and I cannot make that for her, I'm actually just really scared for her.