I need advice about whether I should still persue a relationship with a guy that my mom thinks might be gay?

I have this friend, we’ll call him Derek. He is my mother’s colleague, as an intern. He is only 2 years older than I am and my mother and him get along great. I was introduced to him when he was over at the house once, and I am interested in him and I think he may be interested in me too. However, my mother thinks he may be gay, and she thinks he is going through this period in his life where he is frustrated and angry and doesn’t want to admit to himself that he may be gay. I personally think that he isn’t gay but my mother has a ‘gay-dar’ and has been right about picking out men who weren’t admitting to being gay at first but ‘came out’ later. I like this guy as a friend, and maybe more, but I’m just wondering if you think I should still try to flirt with him etc. or just let it drop. Just a note: My mother came out and asked him if he was gay once and he flat out said No to her. But she is still getting these ‘gay-vibes’ from him from time to time. It would be fine if he was indeed gay, we are still friends and he is a great guy, but I still think he is really cute!!! Advice?