Who is right ????

I set rules for my bf ... For lack of better wording but I have asked a few things that are important to me for him not to do .. I for example when he picks up his 10 year old daughter not to go into his ex house ... It just makes me uncomfortable , and I don’t want to worry what’s going on during pick up or drop off ... Well , I asked him if he had and he said yes once his daughter wanted to show him something ... I am angry !! His reasoning is , he is a grown man and knows right from wrong and wouldn’t do anything out of line and if his daughter wants to show him something than what’s the big deal !!!

He has not cheated , we live with one another and have been with one another 5 years ... Am I wrong for thinking he has no reason in her house or is he correct in his way of thinking ??? Ughh