and guest

So I was talking to Aaron's aunt tonight, and she was telling me that I should plan on inviting all the single people with a guest. Its been something I've been milling over, but unless they are someone that really wouldnt know anyone else at the wedding, I'm not sure I want to pay x amount of dollars for some random person I dont know and have never met before, just so someone can have someone to dance with.

It would make my already large guest list, twice as big. I don't mind inviting plus ones if they have been dating for a reasonable amount of time (I don't want people bringing strangers to the wedding.. like oh we met yesterday!!.. great thanks for bringing them to my wedding and making me pay $50 for their dinner.) If they are living together, engaged or been dating more than x months at the time I send the invites out, I'll send them with a plus one (but I'll find out thier name first). I am NOT sending out people with the wording - and guest. If they don't know their name beforehand, they aren't coming.

I hate giving out "and Guests" - that wording is so open to interpretation. I would love for them to bring their serious significant others, I do not want them to use that wording to bring just any guest they want like- neighbors, kids, cousins, random person they met yesterday, their best friend or any other person that is NOT their date.

Plus I'd rather take that extra seat and give it to someone who I actually know and love.

Is it wrong to invite people who are single as singles? or am I required to open the invitiation for them to bring someone?

That being said, any person that I know won't really know a lot of people at the wedding, I'll include and invitation for a guest. I don't want them to feel alienated... but my friends, who all know each other, would it be wrong to just send them a singular invitation and maybe accept guests on a case by case basis?