Is it wrong for a girl in her 20's to be texting a 50+ yr old man?

For over a year, I've been texting the old man with random texts that's not at all bad, nor flirtatious. He thinks of me as a kid and I think of him as a mentor. He has helped me find the job where I work at now. He has never texted me first, but when I asked him if it's ok to text him, he says it was and that I should not care about what critical things people say of me. I do feel the urge to text him randomly. I wonder if i'm doing something wrong to his wife or to myself. To be honest, I do love his personality.