I've said this before...YC hosts "you want to work at a startup" day. In the past there have been multiple startups that claim "we are a family", "we work hard and play hard" but then handwave ... the only one that was honest at one of the years I attended, was Justin of justin.tv.

Work is a job. If you want to make it a social life, go for it. But let it be your decision.

I've had work situations in the past where many of us were friends and still in contact years later. But, don't let it become your life.