I have a similar story that happened last night.
I went by myself (first time since my separation) to see "The Grand Budapest Hotel" (which I enjoyed!) and it was a smallish theater. I sat on an unoccupied row. Before the previews started, a male/female couple entered my row. The female sat two down from me and it appeared the guy was going to sit next to her on her outside side (i.e., not next to me). However, he changed his mind and sat next to me! So it was her, him and me, all cozy, on an otherwise empty row.
Based on their comments during the previews, I learned they were French, which may explain the guy's not thinking about the fact that he may have been crowding me or possibly making me uncomfortable (if anything, I'd have been fine with the girl sitting next to me). But I felt it would've been ruder if I'd gotten up and moved and I wasn't alarmed or anything - just a little uncomfortable.
He also pulled out his cell phone once during the movie to check something. He was looking at it for longer than just a quick eyeballing so I glanced at it too which is my way of saying, nonverbally, you should put that up.
Anyway, enjoyed the movie, didn't enjoy the experience, b/c I couldn't get out of my mind that a strange male was sitting right next to me and my thigh, if I didn't control it, would touch his. And maybe that's just me and my uncontrollable thighs!