No you are not being unreasonable. Its your daughter who should be making the request not her boyfriend and even then you have a right not to want to do it !
Having a child overnight is not the same as during the day/evening and if she is not sleeping through its even more difficult for you and you are working too !
Your daughter's boyfriend should not be interfering in your relationship with you and your daughter.
Things you find stressful that other people don't notice.
New house and a sloping garden