Valentine's Day worries

Ok so the big v day is coming up and dh asked if I would be okay have our children sleep over his parents house. He's planing something.    DD 10, ds 5, and ds 3 months. I totally trust his parents and know that the older kids will be fine but I'm worried about my little guy. He's so little still and I've never spent a night away from any of my kids at his age. My older two were like 9months old when I let them stay over grandmas house. Am I over reacting and should just enjoy a night of sleep lol?