This one is quite easy. My beautiful 63 year old wife travels back to our previous home city for work about every other month. She stays with her best friend and best friend’s husband so they can be together since we moved away. Her best friend is ill and goes to bed early, leaving my wife and her husband together for the evening and overnight. Unbeknownst to me, this was an arrangement agreed to by the three of them without my knowledge.
My wife is very secretive about her sexuality, especially with me. On one occasion, I had to return there as well for a family emergency and was invited to stay at their home too. During that visit, it was brought to my attention that my wife and her BF’s husband were more than just friends. I witnessed my wife dressing in front of him after her morning shower, specifically stepping into her panties and then lowering her robe to put on her bra. It was a moment that made my heart skip multiple beats as I knew what it likely meant. For my wife to do that, it had to mean they’d been intimate. Heck, I live with her and she doesn’t dress in front of me. We haven’t slept together in 13 years. When we were finally alone that afternoon, I asked if there was anything she wanted to share with me that might affect our relationship, based on what I’d seen. Her reply was “nothing to share that was any of my business, and that it would impact our relationship only if I wanted it to.”
Since that day, knowing my wife has likely shared herself with him has caused me to see her so differently. I imagine them together. I imagine her doing things to him, with him, that she wouldn’t think of doing with me. I imagine her opening her legs for him, not just her body but also her soul. I can hear her see her as she trembles with unbridled passion. I so want what I can’t seem to have, and have no idea how it ended up like this.
I’ve been snooping in her underwear drawer lately to see if there is anything new or different, that might be indicative of her new found relationship. She normally has her daily panties stacked together but I’ve noticed others I haven’t seen before, off to the side. My wife has always wore plain beige and cream-colored panties (briefs), but there are now lacy pink panties off to the side. Several pair. Say what you want. Relationships lose their excitement but when you spend 35 years with someone (married for 31) and you think you know them, it sticks you where it hurts when you find out otherwise. But, the fact remains that my body betrays me. It tells me that I like what she is doing, I crave what she is doing when she goes away... that is, until I ejaculate. And she is more beautiful than she ever has been. To answer the OP’s question, my mental image for masturbating is imagining my wife when she is away from home with her male friend.