Staying up past midnight

I've discovered the secret to exploring the night time, one of the goals on my seasonal self improvement list: start later. We keep starting gatherings at 7 or 8 and finding ourselves tired by midnight. But if you start later, before you know it it's 2 a.m. Husband and I hung with out a couple from his cast (including the guy I find attractive, detailed in the "embarrassment of the day" from the Where I fantasize about the perfect bed linens entry), and they came over around 10 and we ended up talking until 3:30. So they stayed over and we rounded it out with breakfast at Perkins in the morning (it had been years. They still do a decent oatmeal). It was different hanging out with 19-20 year olds, though. They didn't watch the same sitcoms as kids as we did. 3:30 a.m. is more the norm than the exception. And we did feel strange with the whole alcohol thing - do we offer, or no?