Is my fiancee using?

My fiancee and I live separately for now..i saw him for the first time today in weeks..he's been sleeping a lot lately and his eyes are bloodshot, very red, and he said that its because his eyes have been itching and he scratches them a lot..I wouldn't be assuming this but a few weeks ago he admitted his friends were bringing drugs over to his house.? But says he wasn't usin?