My friend from college, his wife and me

So I’m 45 so is my old friend from college and his wife is 44. I’m single never married, no girlfriend, bit of a workaholic. Every summer they come and visit for a few days. They’ve been married about 18 years. She’s always been pretty average, like him and I. 2 years ago she started eating right and working out and now she’s fucking hot. Last night we had a lot to drink. When we went to bed I could clearly hear them fucking, I laid in bed and rubbed myself to her moaning and laughing as my buddy pounded her.