Left DP alone with the kids (2 and 6) for an hour. When I came back my toddler had scratch marks on his shoulder and back. Definitely weren't there before and looked fresh. DP said he can't recall any incident where this might have happened. Its not the first time, it also happened a few weeks ago, they were too deep for him to have done himself. AIBU to suspect he's done this? For context he does have anger problems and regularly shouts at the kids.