The issue here would be you didn't act negatively or reject his advances and to some degree were complicit.
For me it's difficult to see how one would not understand his behaviour was out of order simply due to the fact he was married.

Following that however, there is no doubt his behaviour was out of order as your tutor he over stepped the boundaries.
I am unclear that it would be classified as sexual harassment. This would imply he was behaving contrary to your expressed wishes. Certainly in the UK his advances would have to be unwanted, and sexual or obscene in nature.

We're you unaware it was illegal to be involved with a student?

If you felt obliged or unable to refuse because of his status.

Did he ever ask for anything and you refused?

Don't mistake my questions as me blaming you in anyway, I am simply trying to understand the nature of the relationship better.

Whatever, he sounds like a repugnant and creepy individual, and you have obviously felt harmed by his interactions with you.
It is unfortunate that in our naivety we can get swept up in something that we can later whole heartedly regret. Which is why people in positions of authority are supposed to stand stronger than the rest of us and not allow for these things to take place.Certainly they shouldn't be hand feeding them to the people they are responsible for.

I hope you are doing better now, and have been able too be on some from this experience. All the best.