Son-in-law touching on my wife

Ive been going through this for 2 years now. The first incident happened 2 years ago when my son in law exposed himself to my wife. She advised me he tried to get her to do oral on him. This "Rear End" is married to my oldest daughter who is 22. My wife is 41yrs old. We allowed them to move into our house with my 2 kids who are 17 and 7. They were staying with us briefly because they sold their home and were looking to buy nearer to us. This last incident occurred a week ago right in front of me. As I walked in the backdoor I saw him rub down my wife's back and he grabbed her ass. My wife saw me walk in and she just dropped her mouth and tried to stop me from beating my son in laws ass. I informed my daughter what had happened and got a very confusing response. When she arrived home, my daughter took all her anger out on me and told him that he was "so handsy". I immediately kicked my son in law out of the house and told my daughter the she and my granddaughter were welcome.to stay but he's gone.from under my roof. She is completely acting as if this incident never occurred and is in complete denial
Everyone in my family is pretending like this event never happened and everyone is still talking to him...even after being informed what happened. Am I crazy or is my family not responding correctly to my son in law. My wife is telling me " "what do you want me do". Shouldnt she have responded accordingly right after this happened and not ask me what to do, especially being this being a 2nd occurrence between him and her. I feel alone on my stance because my family refuses to address this horrible and disgusting act. Keep in my mind my daughter has .
Not talked to me after she moved out with him and my granddaughter. Am I expecting to much from my family to act on this??