Did he do this on purpose or was he just not thinking?

I was at work on a ladder counting for inventory. I had a question about one of the boxes and my co-worker came up the ladder behind me to help (it's like large steps, not a painting ladder).

I was kind of surprised since it's not really a two-person ladder and his hip definitely touched my butt. He wasn't creepy about it, just wanted to see the item I was asking about.

(A large lady I work with frequently runs into me with her large chest when she's trying to help me at the computer so I might just be overly-aware about physical contact.)

Was he trying to get close to me or am I reading way too much into this? I would think as a male in the workplace he'd be a little careful about stuff like that. He doesn't know I'm married.