I think most of the time people don't intend to sexually harass others. I'm in the same boat as you; I'm friends with people I work with. So, sometimes they think they can say things around you that they wouldn't necessarily say to someone they were on a strictly professional level with. I guess some people just don't know where to draw the line, and others find that to be harassment. I tend to just shrug it off as an uncomfortable comment that probably won't happen again by the chilly reception.