I agree with CADREAMIN…I love knowing all of my kid’s friends. Everyone is welcome anytime. Somehow we’ll work it out. I have always loved all of my kid’s friends…male, female, romantic, not…what a blessing to have all these great kids and young adults in our lives. So many wonderful people! In fact, its one of the things I love about parenting. Knowing all these great kiddos! (adults now I guess)
Like I said, my Dad was Uber conservative and I lied all the time, I was sort of scared of him!
My DS’s are so much more honest with me about the things I lied about (getting hotel rooms together, etc when out of town), hooking up with an ex. I don’t think it was for shock value, but in conversation and when he plans on going out of town.
Anyway, last year he mentioned he and his GF were going out of town together and trying to find a hotel room at a good price, etc.
Now, I’ve become conservative like my Dad was. I said to DH “why can’t they be more respectful to us like I was to my parents…and lie”. Haha.
D1 dated her now H for 8 years. When she first started visiting him, the parents let her have his room and he slept on a couch. It wasn’t until they moved in together (5 years later) that they started to share a room at his parents’ house. I did the same when he visited. It was kind of nice that his parents replaced his mattress when D1 started to visit them because they’ve had the mattress since he was a child. I thought it was a real sign they liked D1.
I am also not sure if the son’s new GF is expected to stay with OP.
@abasket Not sure whose comfort, to be honest! Whatever the reasons, he had a really nice time and they treated him very warmly.
Update: I don’t know anything yet! LOL…but I plan to find out more tonight…i have to be subtle…like a leopard…and will let everyone know.
The advice here is, as always, so spot on.
The suspense is killing me! :))
Huh. I wouldn’t be subtle. I’d be asking, “How long is GF going to be in town? Where is she staying? Does she want to join us for dinner on Thursday?” 
I haven’t read the entire thread, so I apologize if this has already been suggested. The kids can priceline a hotel or arrange an airbnb in your city for a few nights. Problem solved. Hint: your guests can also do this. Unless you live in the middle of nowhere or something.
It is not only your house but also your son’s. She is not only your guest, but also his guest.
The most important thing is that you make him feel that you welcome his guest and care about the people who are important to him.
Tell him how excited you are to meet her. Then, if you are not comfortable with their sleeping together in the same room, be honest about that and enlist his help in brainstorming solutions together with you, collaboratively.
Talk openly and respectfully with your son. Involve him in the decision making process about where his guest will stay, coming up with a solution with which you and your son are both comfortable.
Your son should know your love for him is unconditional, and the people who are important to him are important to you because HE is important to you.
(Someday, he will be living on his own, and you will want to have a good relationship with him, your future daughter-in-law— and who knows, this could be she!— and your future grandchildren. If you made room for other guests, you can make room for her, if your son would like her to stay- you can get an air mattress for her or your son or you yourself!)
I’m having a hard time trying to imagine how this hasn’t already come up unless I’m missing some details. I’m assuming since there appears to be a question of where she is staying, then the OP already knows she doesn’t live somewhere nearby. If that’s the case, if this were one of my kids the question of where she was staying would have come up in the initial conversation when discussing the fact that we’d be meeting the person for the first time. If she didn’t have a place to stay already, like many others have stated, I’d make room at our house. My boys share a room, so most likely I’d displace one of my daughters and give the GF one of my daughter’s bedrooms.
I personally would never have wanted to sleep together with my boyfriend while visiting, and never did, even after dh and I were engaged. However, I do admit to having sex with my husband while staying at my in-laws. Their bedroom was downstairs and far from where we were. During one trip, after previously suffering a miscarriage after a long while trying to get pregnant, Dh and I did not give up the opportunity while visiting his parents. In fact, his aunt, who is a nun, was sleeping directly across the hall which was a bit uncomfortable. I got pregnant with our oldest daughter that trip and like to think that if somehow dh’s aunt heard us, she must have been praying for us and it was due to divine intervention that our daughter was conceived. ?
That said, wh I would never have slept with any of my boyfriends
It’s so interesting to see how many people wouldn’t sleep with in their parents home (or allow their adult kid to sleep with) a partner with whom they aren’t married. I’m in my 50’s but my parents raised me to believe that having sex should be based on being in a close and mutually fufilling relationship but that marriage was not at all important to that. They also believed marriage was important to a decision to have children and thus emphasizied the importance of birth control. My grandmother was a Margret Sanger clinic researcher and then did so at a university. She was a firm believer in two forms of contraception at all times,one didn’t want to get pregnant.
We have these conversations every year about sleeping arrangements, and there are always a variety of viewpoints. 
So, this IS all about the sex!
Hell, I don’t want 14yo’s doing it at my place, but 20yo is adult, to me. As long as I am not hearing too much yowling and moaning(drowns out my wife and I) then I want my kids to feel welcome at home. Makes for awesome teasing material at breakfast, also.
Intparent, I always find it interesting and informative.
Fortunately, my son was already in grad school when he brought his s/o home.
And every year, skimom reads them, shakes her head, and mutters something about “those prudish Americans.” 
I moved in with my then boyfriend (subsequently husband) back in the 70’s. My father (who really liked my nice Jewish boyfriend) would come to the apartment but refused to go upstairs where the bedrooms were. Unfortunately for him that’s also where the bathroom was.
So far, our kids have never asked nor brought home any overnight guests, and they’re 28 and 30.
I started dating my now husband my freshman year of HS. He came to visit at my parents’ home the summer between freshman and sophomore year and he slept in the guest room on a different floor. No sneaking around at night (squeaky floors) but lots of shenanigans during the day. By the time I was a junior, and had been dating two years, my parents were letting us share a room but in-laws were not. (No squeaky floors so lots of sneaking around). We were engaged by the end of my senior year and officially living together when I was in grad school (he was already done with grad school). His parents were still wanting us in separate rooms and he had a sit down with them and told them that it was making it a downer to be visiting. We married the following Fall and there were no further issues.
I do think though that there is a difference between sharing a room after a few years of dating and right off the bat.
I also think that as people have more long term relationships, with or without dating, norms should probably change. My parents were married less than a year after meeting each other.
Can’t wait to hear the update OP!
Over the age of 20 I gave up. But married now so back to square one and feeling sanctimonious.
Oops just noticed I had a funny sentence at the end of my post above that was meant to be deleted and wasn’t - “that said, I would never have slept with any of my boyfriends”…that was supposed to end with “while visiting either of our family homes” I later edited my post and didn’t take out that last sentence which makes it sound like, uh, I never “slept” with anyone until marriage. ?