without making it too obvious or blatant? My neighbor has a friend I think is really cute and I want her to introduce me sometime, but I don't want to make it seem like I'm asking for a setup in fear it would change our long time relationship.
You've got to consider if she would actually be bothered by your asking...
Play it out in your head, would she care if you asked?
Just ask her what they have been doing and see if you can join them in something...