After years of marriage thinking I might just be asexual?

For context I'm a male married to a female in a normal and healthy relation. Never had another partner nor interest.

With a close group of friends we were talking about our experiences when we were young about relationships, and while talking about crushes and relationships I felt the need to lie just to fit in, I had to say I had an imaginary crush because otherwise if I never had a girl crush then it must have been a boy or something.

This left me reflecting for a while, I never had a crush, I can notice tell someone is attractive regardless of their gender but that doesn't spark anything on me. Never had the impulse to have sex.

I'm okay having sex, and I think is enjoyable but never actively seek for it, for years I blamed maybe I just have a low libido or something...

My current partner came to be just because we were friends for a long while, and we felt comfortable near each other, and I do enjoy and love having someone close that you can trust and have experiences with.

But I feel like I shouldn't be having this many doubts at this point in life, did I just assume I was heterosexual just cause I was okay with it? never reflected on it and realized that people do have sexual urges and things like that, even the whole concept of cheating always felt odd to me, like what would drive you to engage in sex with someone other than your best friend.