my private students' dad is love bombing me and encouraging tax fraud

[Joseph Maynor]

You can establish boundaries energetically and through behavior without having to say anything, at least at first.  If he doesn't get it, then you may have to start to say.  

[Lyubov]

Sounds like an amazing client to be honest, pays for canceled lessons and increases pay without having to negotiate. I tutor as well and that sounds like a dream….

But you need to learn to enforce boundaries. He is kinda flirting with you. Don’t send photos to him, put a wall up if he advances on you. Keep it professional and be strict about it.