If "friends" are what you call people who just want to mooch off your rooftop, especially if it has a pool.
Coincidentally, there’s a story in today’s WaPo about the social climbing side of private outdoor spaces in urban areas, and it’s not a pretty picture. See, in this world your goal is to progress from rooftop to rooftop pool to in-ground pool with grill and finally arrive at belonging "to a country club in Chantilly. It has a pool, horseshoes and a snack bar. The life." (Chantilly’s a wealthy exurb of D.C.)
While I totally get feeling desperate to be outdoors when the weather’s nice, to everything else in this story can I just say: Ick!