should i let my 18 year old sleep in the same room with her bf?

My daughter has recently approached me asking if i would be comfortable to let her and her boyfriend sleep in the same room once they both turn 18. They are both 18 in october within 2 days of each other and have known each other for 11 years and have been going out for about a year now, i trust her and i trust him. I know that they are both sexually active as she has told me this. (they have only been active with each other). I have ensured that she is on the pill and they use contraception and we have had the "sex talk". Once they are 18 they are technically legal, but im not sure i feel comfortable. At the moment he stays over twice a week in separate rooms (my son's room is in between theirs). She has told me that the reason she wants to stay in the same room is just to cuddle and feel "all warm and cozy". Im starting to think that there isnt much reason not to let them, because they have sex whether they are in the same room or not, they are protected, they are in love, and just want to be with each other . So what should i do, should i start letting them?