At that age, you gotta have rules.
Not letting her just do her own scheduling for socializing.
If that were me, at that age, my parents would not put up with it.
A 16 year old... with a boyfriend, is not an adult, making those same choices. The human brain is not even fully developed until 26 years old.
And what about her homework? And household responsibilities/chores?
If she has none of those criteria for being a PART of the family, then yes, you are a bed and breakfast.
Next, where is your Husband in all of this? He AND you have to create a set or rules of conduct and expectations. She is way old enough for that.
It doesn't matter if she is a straight-A student or not... she is a part of the family, and there are obligations to that, and to her parents. Regardless.
I think, the leash is too loose. Not that "family" is a "leash"... but you know what I mean.
You AND Hubby sit down, and talk to her. It being not a "punishment' but it being HER responsibilities and familial task to have the family as a "priority" TOO.
And, yes, your 13 year old. Whatever happens now, will be a precedent... and the 13 year old will probably regurgitate to you, whatever you "allowed" your 16 year old to do, or not. So, wrangling that.
And so it seems she can come home whenever she wants. And go out whenever she wants. And hang out with Boyfriend whenever she wants. And do whatever she wants. She's like a "tenant." But does not pay rent. Wow!
What about curfews? What about designating certain days/nights she can see boyfriend? What about designating certain nights she has to have dinner AT home? What about chores? Designating that too, and a host of other parameters.
Its not about "controlling" her, but how to be a part of the family.... and her being respectful of that... she can do her things... but there needs to be a bottom line, right?
AND the most common sense thing to me would be: WHY can't Boyfriend come over to your house TOO, to hang out with your daughter?????????
AND what the heck does your daughter/Boyfriend do at his house????? Do you even know? Do they hang out in his bedroom? What are the "rules" there for opposite sex hanging out???? Or do they even hang out at his house? Or do they then go out elsewhere, and do you KNOW where she is or what they are doing????
Does she know about sex and birth control, for example?
What is their "relationship" like? Do you know? Does she tell you????
Also, at 3:00 in the afternoon, most parents aren't even home themselves, from work (if both parents work).... so um, until the boy's parents comes home... your girl AND that Boyfriend, are basically BY THEMSELVES....???? Doing what? I don't think its just sitting in the living room watching TV until 9:00pm....
Also, your daughter should be ASKING permission, to go out. Not just coming and going...
all the best,