Gouramies don't 'pair up' in the familiar manner of cichlids. If you have a male and female, the male will probably start chasing the female around as soon as he is in breeding condition but that doesn't guarantee the female's condition or cooperation. In fact, keeping pretty much any gouramies as pairs is generaly a bad idea as the male picks on the female and stresses her out (and that can cause death). Trios are better (though I wouldn't advise adding another female - add two more of the same size so the 'intruding' newcomers don't get picked on and rearange the tank a bit beforehand ).
But to answer your question more succinctly - no, there is no guarantee they'll spawn. if the male builds a nest and the female is gravid, they may well try. Even then, you probably won't be able to raise the fry in a community tank and you need to keep in mind that, as standard, you'd have to remove the female after spawning and the male once the fry are free-swimming. So, in a community, the fry/eggs are likely to get eaten and the female bullied when the male starts guarding 'his' nest in ernest.
edit: Hold on - your 'female is a bit' .... what? Do you mean 'she's' a bit dark - cause then you have another male who ahsn't colored up yet (and may never do so) because the dominant fish is preventing him (in effect) from doing so.
no i deffontly have a male and female with a doubt and she is getting very chubby and she follows the male when he flears his fins out and arfter 5 mins together the go separte ways