Love makes the world go round.
Whom your child loves isn't the issue, the issue is that they are loved at all, that your child can give love and receive it, is a blessing. Stop dwelling on the sex, that isn't any of your business even if your child is heterosexual. You aren't invited into their bedroom, only into the life and family of your child.. Your adult child. Be happy for them. Do not throw your gay children away, they are the same children you loved and raised. just accept and love, that is part of being a parent.
Proud parent of 3 adult children, one of whom is gay.