I caught my dad with a prostate massager.

I'm an 18 year old girl who has been in quarantine for some time. I was too sick to go the grocery store today so my 44 year old dad offered to. I was on the toilet but he pushed the door wide open while he was walking by and I was so mad because of privacy. He came home and I didn't have the guts to tell him off. Later on, I accidentally walked in on him and he had this big purple thing in his ass. He looked so embarrassed. He told me put my hand up his ass to feel it and it felt really weird, I told him it felt weird but he told me it feels good for a man to have it up his prostate and that it's really normal. He looked up a video on youtube for me and started playing this week. It was just a bunch of nude men jerking off with those things up their butts and he started jerking off while I was there. He asked me if I wanted to join in? I didn't know what to say so I was like sure. And we both just sat on the bed together jerking off while he had it up his ass. I kissed him and told him I loved him afterwards and he told me he loved me too. I told him I want to do it again later, I don't know what to do.