I think attempted mounting is grounds for sexual harassment. If your mananger is going at you like a dog in heat, well, thats just gross 😛
In all seriousness, even if he's the manager, there's ALWAYS a bigger fish (Episode One reference, ahhhhhhh!). He has to report to someone if its a franchise. I'd suggest going with your idea to notify someone at the corporate office. They'll be able to direct you in the right direction. It doesn't matter if "restaurants are a sexully charged atmosphere," if its interfering with your work, you don't need to put up with it. Write a letter or two and make a phone call. Be prepared to face the conswequences of the manager finding out. He will probably make it very hard to work there, and you may have to quit. Re-notifiying the corporate office won't help then, because if they were dumb enough to tell him who it was that complained, they obviously don't care about it.
I've been in a situation of sexual harassment only once. It was in high school, and we had a male art teacher that was making several of my female friends uncomfortable. They had talked to me several times about it, and I mentioned it in passing to my older sister. She called the school, without telling me first, and told them about it. Guess who got hauled into the principal's office and had a conference with the principal and superintendant. I didn't want to be drug into it, but they were my friends, and they didn't want to report it themselves. He was a big guy, and I was genuinly (sp?) afraid for their well being should they be in the room working on a project alone with him (it wasn't uncommon for the better artists to be behind on projects, and come in during free time to work on them). I refused to give them either of my friends names (at their request), but having witnessed the actions first hand, I think they believed me. Eiher way, he acted "neutered" the rest of the year, and any knowledge he had of the complaint would have involved me, and not my friends. I don't think he was told who complained, because he never changed his actions towards me. I wouldn't have put it past the dumba$$ administration to tell him it was me, so I was prepared for it.
Nevertheless, good luck at your job with your situation.