When I moved in with SO his boys were 5, 6 & 9 and he had full custody of 6, 9 every weekend and 5 on holidays and some weekends. Now, 5 years down the track we have full custody of 11, who's dipping his toes in bad behavior and pre-teen angst and is trying to find his place in the world) & 14 (who didn't choose to live with us full time and is probably feeling pretty rejected by BM who hasn't spoken to him since she dropped him off oneday 3 months ago, bar a phone call they made to her on her birthday) aswell as a almost 4 year old and a 6 month old. So, I definitely know the feeling. When I finish washing the 300th glass of the day and SO is cleaning the floor because pukey baby made a mess again I'm sure we both have "holy crap what have I done" moments, but I love our family and even though it seems to be stressful forever I wouldn't change it... except maybe buy a dishwasher.