My 80 year old dad and 77 year old step mom both have Alzheimer's and my dad wants to grope her all the time. Any advice? Solutions?

They have been married for 30 years and are both living together in assisted living (for the last 10 months). He had his prostate removed decades ago. However, now he wants to "play" with her (she also wears depends). She has absolutely no desire and keeps asking me if I can find her another place to live, that I should have her "committed" or that she would rather be dead than have to deal with him. He gets aggressive and has temper tantrums when she tells him "no". She has also feigned chest pains just to go to the hospital to get away from him - trouble is, he always goes along. He is afraid to be alone. The doctor prescribed Seroquel for the times he "acts up" but I believe it has to be in his system for a while and not on an "as needed" basis. This has been going on for quite a while and the assisted living facility has threatened to evict them in the past saying they aren't equipped to handle such situations (they are extremely understaffed). Any advice would be greatly appreciated. Thanks!