My stepbrother stays to sleep in my sister's room, when I go to wake him up I see that his penis is very hard

In my house last night there was a family party and my step brother stayed to sleep and my sister lent him his room, this morning I went to wake him up so he could help me tidy up the house and when I entered the room I saw that his penis was very hard and I wanted to try it, I touched it, sucked it and we ended up fucking before everyone woke up