My friend [28 f] was propositioned to have sex by her boss [65 m].

Her boss earlier in the month asked to schedule time with him to visit some locations relevant to work. She did so and when today came, instead of going to do a site visit, he took her to get a beer at a brewery and then to his home. They spoke of work related topics the entire time, besides when he gave an "historic" tour of his home; this included walking around his property, getting a ride in a Model T, and on an old tractor. The tour was loaded with insinuation that, because of her interest in farming, she could do work out on the property to get experience with tools and practices.

When all of this was said and done, she stated that she was ready to go home since they had been out of the office for the past 2.5 hrs. He began talking about a proposition and all the while she was heading to the vehicle to leave and had already buckled in when he said "I have a proposition for you, but I do not know how to say it. My wife does not satisfy me sexually and I find you very attractive. What do you say?"

Her response was "No". He asked why and she explained that she is in a relationship, he didn't find that relevant, and asked why again. She said she wasn't feeling well (she was out sick earlier this week), at this point she was so freaked out by the situation and how she missed the signs, that she didn't know what to do. In the end he took her "No" and drove her home. BUT, he also said "Forget this conversation ever happened. Forget we ever came here, if you were asked, we were caught in traffic."

She feels guilty because she thinks she should have seen it coming and she also fears her personality may be too friendly.

Her questions are: Do I report him to HR? Do I tell him that I am reporting him to HR? Do I forget it ever happened and pretend we are okay as boss/employee? Do I risk his job and his relationship with his wife because he made me feel uncomfortable? Do I play the role of sexual adviser and send him to girls who may be into getting paid for their personal time?

TL;DR: Female was propositioned by her older male boss to have sex with him. She does not want to reciprocate. Needs advice.