Roseycats, it might be too hot or one or both of your crosses are not that fertile. Some are very hard to set pods and some are only pollen fertile, while others are good both ways. Lack of moisture/water could also be a cause. Mike
Try going out the next morning and snipping the spent bloom off at about 1/2" to 1" from the scape, leaving just the stub of the bottom of the bloom. This takes all the stress of the weight of the withering bloom off the forming pod. I do this with all my fertilized blooms. Keeps people from deadheading the blooms thinking they are helping you out. Also looks so much nicer than all the old blooms hanging on. By doing it the next day, it won't affect the fertilization.
Is the pod parent nocturnal? If so, try fertilizing late at night after the new bloom opens. I have even forced the petals open on the next days bloom to fertilize late at night.
If you are trying the same pollen, try using a different pollen, even if you don't want the seeds.. Your just trying to get the tet in pod production mode.
Another thing would be to shade the plant you are trying to get the pods set on. You will have to be creative! I once used two lawn chairs to hold up an old pillow case to shade a reluctant pod setter.
Are you sure the both plants are fertile? Some are not. If they are named, not seedlings, check the AHS database to see if any plants were registered with your plant as a parent.
An old trick is to hit a tet with diploid pollen a few times. This will often produce an "air pod" that will not be fertile, but will get the reluctant tet in the mood to set pods. I have never tried this, but have read about it for years, and know people who have had success.
I am NE of Columbus. I don't usually try pollinating if it is over 88-90, and try to get all crosses made by 10:00 a.m. You may have to collect pollen one day to use that night or early in the morning to get pod set.
Also, we have been really dry here. Try watering the pod and pollen parent to be sure they have adequate moisture. Plants will often not set pods, or abort pods if they are under a lot of stress.