No sure if this belongs in teens or in relationship so ended up here instead 
dd is preparing for her A levels. Obvioulsy she should be full on in the middle of her revisions. Her mocks were ok but not as good as they could have been. She also has a bf and wants to spend time with him. She is doing a competitive sport so is busy a lot (most) of the weekends because of that.
That's for the background.
DH and I have a difference of opinion on how what to say to dd when she wants to go out (lets say friday evening with friends or staying at her bf).
I think she is 18yo. it's up to her to decide what to do. The most I can do is ask her if she has done x and y or is feeling up to speed with her revisions. I know she can put her head down and work hard. I am just worried that (like a lot of students!) she'll leave it too late to do everything.
DH thinks it is disgraceful she is going out like this. He has an issue with her going out (and take a couple of cans of cider!). He has an issue with her staying at the bf. All because he thinks she doesn't work enough. Basically telling her she is lazy. But doesn't have any issue with her doing her sport and spending all the weekend doing that, even taking time out of school. He is actually encouraging that!
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It's creating lots of tension at home. Between dd and dh, between me and dh...
So how would you handle it?