I don't know about that "cum jar" ...
I think I would find that definitely a male ego killer!
I was at a convention, years ago, and met this attractive lit'l blonde at the motel bar. She was professionally dressed, and she seemed to take a chatty interest in me, so I bought her a couple drinks. She invited me up to her room for a night cap. (she wasn't a ****** as she never mentioned money).
Anyways, when we got to her room she excused herself to the bathroom for a few minutes, and while she was in the restroom, I kind of pondered around the room (it was a nicer room than mine) and I just so happened to glance down into her waste can ... yup, you guessed it ... a used condom. I also noticed an ashtray with 4-5 burnt cigs in it, and I hadn't seen this girl smoke ... had I seen her smoke, I probably would not have been in her room then. Anyways, it killed every ambition I had to nail this cutie ... and the weird thing is, I had every intention of using a condom myself. Anyways, I made an excuse and said my goodnights and promised to catch her the next night. However, I didn't even go down to the motel bar.