my little sister lives with me and somehow she got me to take in her friend who's parents left her alone. They had been pretty nice(never fighting, always getting homeowrk done, and they never get in trouble) but one night i went to check on them and i went to see my sister first but i saw her friend in the bed with her. they weren't having sex they were just sleeping all cuddled up together. is it ok for me to let them do this?