What do you say when your girlfriend tells you she’s bisexual? #bisexual

What do you say when your girlfriend tells you she’s bisexual?
Be glad that she still chose me even though the dating pool just doubled
You have to one-up her to show dominance. Tell her you are a trisexual.
My girlfriend is bi and more homoromantic leaning however she is completely infatuated with me and doesn't want to be with anyone else. The only difference it makes in my situation is that we feel comfortable seeing an attractive female in public and going "damn she's fine" together lmao.
"You mean you were checking out girls, but still chose me??"
"Thanks for telling me".
“Please stop trying to change the subject whenever I suggest we watch my new copy of Minions: The Rise of Gru on blu-ray.”
I have a girlfriend?!?!
"Hi bisexual, I am boyfriend"
I think my boyfriend just said “I know, you’ve literally had sex with women before.” (I did tell him I’d had sex with women before)
"That's gay."
Using it to my advantage: There are boobs in this movie too.