Lesbian Affection Is Considered Bisexual?

This is one of the most insane quotes that I never knew would enter my ears.

One day, I was having lunch with a friend of mine. I haven't seen him in a very long time. During lunch, we were talking about our past relationships and how we learned from each of them. I haven't been in a relationship since February. He recently broke up with his girlfriend of four years, which is something I applaud him of. He used to have a reputation in high school as a playboy.

I still have older friends. He is almost entering his thirties.

The conversation then went into another direction when we started looking at couples around us at the restaurant. I pointed at a few people and saw how cute they were. Suddenly, we saw these group of friends double dating. They decided to play a little make out game with each other. The guys kissed each other first, followed by the girls.

"That is so cute," I said.

My friend gave himself a second. Even though he has gay friends, he has never seen them kiss each other. He looked at me and said "They must be secretly gay."

"Oh come on," I responded. "Now you're going to say the girls are gay because they were kissing each other."

He looked at the girls making out and said "Technically, that's bisexual."

My mouth dropped when he said that. It was like listening to someone who is so sexist. He isn't, but that quote was. If you looked carefully at the people sitting at the table you can tell that they weren't bisexual. They were best friends on a double date, and decided to have a good time for the night. When I got home and sat down watching sitcoms on the television.

Why is it that women affection is considered bisexual while men affection is considered gay?