@dansup Good luck!
This is of little comfort, but if genealogy is their [main] concern, your being gay does not imply that they won't have *genetic* grandkids. In 10 or 15 years (you seem quite young) it might be even possible for two males to pass on their genes to a baby.
https://www.iflscience.com/health-and-medicine/two-father-babies-could-soon-be-possible-no-egg-donor-required/