With some regularity, a writer—any creator, really—has to get out of the chair and into the world, or what he or she has to contribute will fail to interest anyone for very long.
An invitation to a party is one such opportunity, but some writers, so used to working alone, find excuses not to attend. If this is your inclination, you might reconsider for the sake of your work.
The one caveat is to say nothing of your embryonic work. Too much, too soon is deadly. Instead, just have a good time. Draw the other guy out, which is easy, as the story that interests a person the most is his own. Ask your questions. Listen.
Presumably, you will be good company, as is required. And from your end, you will likely have more than just pleasantries to churn over as you get ready for bed.
You might have something striking, or meaningful, or puzzling that will be useful to you in your work. And though you might be hard pressed just then to articulate it, if you can jot down a few words, a fragment, or maybe even an opening line—it’s a place to begin later.
And then forget it and go to sleep. Whatever struck you, whatever penetrated, will marinate in your dreams and count for something in the morning.