Parent-Teacher conference for my oldest son was tonight. My lovely child is failing math mostly because he's not turning in work. I asked him if there were any concepts he didn't understand and he said that there were a few that were giving him trouble. I asked him why he hadn't asked me for help and he said that he didn't know if I could help him. His teacher pipped up that there were tutoring options. I looked at her, then looked at my son and said "Son'sname, have you ever told your teacher what I did for a living for ten years?". He looked sheepish and said "Math Teacher". His teacher laughed, but my brain hurt. Umm, honey, I have a master's degree in math, taught 7th grade and community college for 10 years. I think I can help you with Algebra I. UGH.
Yes, it is ironic and funny. But you know what? I can kind of get where your son is coming from.
He's having trouble with MATH!!! The very subject that his Mom obviously "gets" with no problem at all. The fact that it seems easy to you doesn't help his self esteem at all. The fact is that it is probably quite embarrassing for him and he fears that it would also embarrass you that he doesn't seem to 'get' math.
You might get farther by saying "You know, Honey, your Dad always had a really hard time with math (or something similar if this isn't true). I get that not everyone finds it easy. But I'm your Mom and I also happen to be a pretty darned good teacher! I really can help you with this if you'll let me. And I love you for you. It's okay that you don't have the same comfort zone with math that I do. I'm sure there are things you could teach me about too. So let's get to work on this -- together!"
I've had that discussion with him, though without the Dad part. My ex-husband disappeared 10 years ago and hasn't been heard from since. Actually, it goes more like this: "I know not everybody finds math easy. I taught students who had a hard time with math for 10 years. I'm really good at breaking things down for people who find the concepts difficult. I'm also good at finding different ways to explain things, so if one way doesn't work, we can try another." I taught in an inner city school. Most of my students had a hard time with the subject. I also taught a lot of college-prep classes at the community college, so I'm very familiar with students who have a rotten time learning math. I think that's what frustrates me the most. If he's having trouble with math, that's fine, but that's also the exact type of student that I specialize with. When I tutor, I advertise for students with math anxiety or a feeling of helplessness when it comes to learning math. I think I'm just frustrated that I can't seem to get through to him that it's okay not to be good at everything, and that this one topic is one that I'm really very good at helping with. This is the child that was reading Victor Hugo and Leo Tolstoy at age 11, speaks and writes fluently in formal Arabic and is conversationally fluent in Spanish, French and Portuguese. He's very bright, but more language oriented.
I'm going to suggest one other point to consider, from my own experience, just in case it's helpful.
I am a language-oriented learner who struggled with math and am a child of a math-oriented father. Despite his love for me, thorough understanding of the subject, and willingness to break everything down, my father could not teach me math.
Not because he wasn't a good teacher, and not because I wasn't a good student. Because, at the core, he was always my father and I was always his daughter, so we never could get into a pure teacher/student set of roles. The parent/child roles took up that space. (Eventually a high school boyfriend helped me out. Apparently the boyfriend/girlfriend roles took up other space. Ahem.)
In my opinion parenting and teaching are each remarkably difficult jobs and very different roles in a child's life. Often parents can also be teachers for their children, but in my experience when a big learning obstacle appears it can be really helpful to separate the roles. With this in mind, maybe looking at another person to tutor your son would be helpful. Not because you don't have the teaching/tutoring skills to do the job, but because for this particular student you're not the right teacher (because you're already his parent). I also wonder if this is why he's been reluctant to ask for help, even if he couldn't articulate it this way.
Good luck!