I (21M) accidentally hooked up with my girlfriend’s dad (62M)

Okay, so for context, I have a girlfriend of 2 years with whom I have a very good relationship. I even planned to ask her to marry me in a few weeks.

We get along really well, and have lived some great experiences together. We trust each other a lot. We have been wearing blindfolds whenever we have sex for the last couple months, because we thought it would be a good way to spice things up.

So yesterday, her parents invited us to their house by the lake. Her mom has never been very fond of me. Her dad, on the other hand, has always liked me, and we engage in conversation very well.

We had a couple drinks and the evening went by really pleasantly. After a couple hours, my girlfriend suggested that we went upstairs. I said I’d be right there.

So I went upstairs, and I suddenly felt in the mood to surprise her. So I took all my clothes off and I layed on the bed with the blindfold on.

I heard my girlfriend open the door. She sat beside me and rubbed my back with oil. It felt really good. I suddenly felt her lips touching mine. They felt a little bigger and drier, but since I was drunk, I didn’t give it much thought.

I then felt a warm breath going down on me. I received a nice service from her. She then asked me to fuck her. I did so. I need to clear up that her dad has a fairly girly voice, so I didn’t even think twice.

Penetration felt quite different, but oddly good. I asked her to use our dildo and penetrate me. It felt way smaller tho. After that, she cuddled me and we went to sleep.

The next morning, I woke up to his dad sleeping next to me, naked. I tried not to say anything and leave the room.

I had to walk naked through the forest before getting home.

I feel good about what happened, but I don’t want to hurt my girlfriend’s feelings. Any advice on how to leave my girlfriend for her dad.