I've done weekend-long drop-in/drop-out parties many times before. Every single one, while exhausting, had been incredibly memorable and will be remembered for the rest of my life.

You don't have to be around for the whole thing either, you can easily take some time to read or otherwise relax if you have enough friends coming over - nothing weird about friends hanging out in your house without you present.

I used to give out house keys to most of my friends and encourage them to come by whenever - if I'm not around, if I'm busy, or just plain exhausted, I won't hang out, but it's still a safe and fun place for people to gather. This often led to spontaneous 'parties'. I remember once a friend was in the area and came over with ingredients for a dish she had been wanting to create. Enough people ended up randomly showing up, it led to one of the most memorable and wonderful dinner parties of my life!