Our family takes turns watching over my grandpa since he's 92 and cannot live independently without assistance.
I was at my grandpa's house over lunch and "Alice" stops by which was unusual- she is the mother of a man who is closer to my parents and they know each other through church- I'm not that close to Alice.
My grandpa and I were eating at the table in the kitchen when Alice came to visit. After some chit-chat (asking how they were doing, talking about family, etc.) Alice started kissing my grandpa and he placed his hand on her breasts under her shirt. They continued to kiss and touch each other and I was silent. It seemed like they were pretending that I was not present while doing all of this. I kept my eyes adverted but I could see that my grandpa was pulling Alice's shirt as much as he could to expose her breasts. I quickly finished my meal, washed my dish and left quietly without saying anything. I went back to work and Alice was not there when my brother came to stay with grandpa that evening.
I tried to make my movements not come off as rushed or aggressive in any way and tried to act as if I was unfazed. But honestly I was very uncomfortable and wouldn't want to be in that situation again. I feel bad for leaving my grandpa when I was supposed to be watching over him but he was unattended for a few hours at most.
I think I could have handled the situation much better than I did so I'm looking to talk over this with my grandpa in case it happens again.
I want to express to him that I care about him- I do not mind his romantic interactions or relationship with Alice- but the situation for me was uncomfortable and I was not okay with the intense PDA that happened in front of me. I'm not sure of an effective way to communicate this to him.
Misc. notes that may or may not be relevant on the situation:
I'm a young adult living in the United States
My grandpa can hardly walk and has some cognitive and memory issues; Alice is about 70 years old and can walk and drive
My family doesn't have anything against Alice but we do not trust her to care for grandpa
My grandma (grandpa's wife) passed away 25 years ago and he did have a girlfriend for a few years but she also passed away a couple of years ago. Alice's husband is also deceased but my family believes her son would be very angry if he found out about this situation.
My grandpa is very religious and conservative- so this behavior seems unusual but I understand that his desires are probably very human/natural