Strange dating issues

[Mrs_MQuve]

Hey everyone,
I've been having some strange issues with dating.  My two Sims are CRAZY about each other (I planned it out so they'd have maximum chemistry, heh) but whenever they go on a date downtown, after a few minutes some need desperation bubble flashes over the guy's head and he takes off.  A few notes:  1) I have been playing as the girl when this has happened  2) This has happened multiple times  3) Each time the dates were going well, because they have incredible chemistry and I was satisfying his wants.
I did invite him over one time and made that a date, they woohooed and had tons of fun.  I did get a dream date, but afterward the same thing happened as on the community lot.  It was so weird, getting two messages at once - one that he couldn't wait to see her again, another that he was taking off and didn't she care about his needs?  Geez.  Well, the next morning she got a nice bouquet of roses, so I know where he stood on that.
Sorry that was so long, but it's such a baffling problem I needed to explain it thoroughly.  Thanks!

Edited:  I forgot the most important details... I have only the base game and Nightlife, and I do have hacks/mods installed, but none that involve dating, I don't think.

[Engram]

For some reason almost always sims arrive at the controllable's house busting to go to the toilet and often hungry. So make sure that the date gets a chance to go potty even if your controllable doesn't need to. And make sure you feed them. Fun and woo hoo are not enough to take care of all of your date's needs  If you went out with the person of your dreams and they never fed you or let you go to the toilet, you'd be unhappy, too

[kinnika]

You said that hacks / mods didn't solve your dating problems. However, if you have the Insimenator, you could easily solve these annoying little woes by using the Motives Adjuster, Social Adjuster, and the two relationship adjusters if you'd like. It really helps when I'm trying to get two people together. In fact, you don't even need to use all of them at one time. You can use just one to help that special date along.

[Mrs_MQuve]

Engram - Oh yeah, I remember reading about that somewhere.  Here I am trying to satisfy his wants bar, which is full of singing and dancing and such, when he's starving and has to pee! Hehe.  Thanks!

Kinnika - I don't have any mods or hacks that would affect the dating mechanism, as far as I know.  I don't have the Insimenator (I've just been lurking at the site for a long time), but it's probably a good idea.  Thanks!