Just Another Night of Being Used

I'm married to the idea of open relationships now. She's out with another man, and I'm alone in our bed, missing her touch but also feeling hollow inside. My hand slides over my skin, seeking comfort where it's not truly needed. Fingers tease until they find what he touched just hours ago. Then, pressing hard against myself, I picture him, his mouth covering me, moving against me as if it’s still happening now. But it's just a cold bed and an ache that won't be satisfied. Does this mean there's something wrong with us or am I the one who can't let go of monogamy?