Trying to hide my boner in front of my gf’s mom

This happened a while ago, but I was staying over at one of my exes parents place over the holidays. It was the middle of the night and I had woken up. We were staying in the guest bedroom after a few minutes of rolling around trying to fall back asleep I decided to go to the bathroom. Thinking one else would be up in the middle of the night roll out of bed throw on my boxers with a huge boner. I walk out of the room and down the stairs to go to the bathroom. As I get to the bottom of the stairs, I noticed the kitchen light is on. I take a few steps forward and look over to my right. I’m in the dark is my girlfriend’s mom sitting in the dark reading her Kindle. She looks over and says “oh my” and then pulls her Kindle up to her face to hide her view. I scurry off to the bathroom and see the in the mirror how apparent the outline of my hard cock is. By the time I get out of the bathroom she’s gone upstairs and back to bed. The next morning while she was serving breakfast. She made a few size comments about the sausages she had served with the eggs. I’m pretty sure I also caught her looking down a few times.