Yes, I do talk about and show aspects of second life with my partner, circle of friends and sometimes my work colleagues.
My partner is active in SL as well, has been since before we met and before I started my account though we didn't actually meet in SL.
We spend a lot of time in SL together as it is and so are often discussing it.
Mostly other people I have talked about SL to hadn't heard of it before and I have tended to describe it as a virtual 3D place that exists as an online space shared with other people. These days that takes a lot less explaining as people are more familiar with 3D worlds/games than they were when I started. I think they imagine mostly like a chat/meeting place where you can customise the way you look.
Some of my newer friends who haven't heard of it before are actually quite interested in what it is, etc. I get a lot of interest about the clothing and fashion related aspects from my female friends but mostly that fades when they realize they still cannot use it on their iPhone/iPad and need a computer with a decent graphics card for it to work well. I get the impression that they would be happy to play if it meant shopping for clothing, dressing their avatar and accessories and socialising in a shared chat room all on their phone. That would be enough for them as long as it was easy and simple. They are not interested much in building stuff, role-playing or flying/sailing/driving or anything too complex for example.
They don't think that spending money inworld is that unusual though because some spend a fair amount on items for Free-to-Play games on their phones.
That pretty much covers the mostly not-much-interested-in-computer-stuff crowd. Some of the people I know who are more tech savvy ask, usually with a smirk I might add, "Isn't that the place with all the people who dress up as animals?". They think it is populated mostly by furries (they don't actually know this term though) who also dress that way in their RL (they often seem fascinated by this part but don't really know anything about it really). They aren't sure why they have this impression though and I have never been able to find out why that is the thing they associate it with most.
Hardly anyone I have ever mentioned SL to raises or are aware of the sex aspect unless I mention it.