Coming Out Support Group
This community is dedicated to the challenges that gay men and lesbian women face, both between the partners in a relationship and from other influences (family, society, etc.). Find support and talk to others who may be facing the same challenges, and share your experience.
As for my sisters, my oldest sister knows I believe I'm a lesbian and is totally okay with it. She's the only other person I can go to. Its the other sister, the middle child, that I don't know how she'll react.
Seems to me your Mom has a pretty good idea already? She might display disgust when its on TV, feeling that it is an inappropriate display of affection. When she is concerned about her daughters happiness it becomes something totally different.
I agree with Dan, go to your mom in private maybe with the older sister [she knows and can support] and explain things.