Blue balled

I'm single but always had this fantasy with my ex.

She'd come down and sit beside me on the sofa and cuddle up. Then proceed to start stroking my cock and taking it out of my trousers.

She'd then grab my balls tightly and begin to suck on my shaft. Between mouthfuls, she'd be telling me about a guy she works with has started making moves on her.

Trying to gauge my opinion with her skills she would work her magic getting me agree to let her get involved with said colleague.

When I finally relent to her wishes she would stop and say thanks, giving me a peck on the cheek and leaving me extremely frustrated.