Walking or standing really close to someone you don't know who has an umbrella when its raining and you don't have one. Done in a casual way to piggy back on their umbrella without them noticing that's what you're doing.
"My friend forgot his umbrella today and i noticed him rain ghosting different people all day to keep from getting wet."
A common phrase used when playing Call of Duty: Modern Warfare 2. Sexy Goggles are special head attire that make the Russian terrorists look much more BA. Possibly meant to be night vision goggles, they are never in use in the game so serve no purpose but to look good.
"While playing Spec Ops we had to make sure to stay focused and not get distracted by the sexy goggles all the enemies were wearing."