One. They are just cat suits. Also, I think the characters never appear before or since so there is no context that can help.
My best guess is that the "hetero" part is her providing makeup and costumes (including the mouse to be thrown up) while the "homo" part is the singing...
Hetero - from the Greek ἕτερος meaning different or other
Homo - from the Greek ὁμός meaning same
Irregardless of the orientation of the people involved, if its two different gendered people having intercourse it's heterosexual intercourse. It just wouldn't be any fun for the people involved.
I believe the sex would he heterosexual, but the parties would still be homosexual. This happened a lot in lavender marriages. The fact they had sex to produce children didn't change their sexuality.
Similarly, e.g. two bi men getting married is a gay wedding, even though neither party is gay. The relationship can be described independently of the people in it.
Homo - same sex intercourse, hetero - man and woman having sex. Their orientation won't make intercourse gay, it's between different sexes so the act itself is heterosexual.
Nowadays hetero has been redefined to better reflect gender diversity. Homo is same gender, hetero is different genders, even if the gender are not man and woman. This includes non-binary people in the definition, as long as they are not the same gender, is not homosexual. And to be honest, it ties better to the word, etymologically.
Also bisexual now means homo and hetero, not men and women. I'm still confused about pansexuality in this definitions. I also might have got something wrong in this explanation as I'm a cis straight dude, who listens to other people saying this things.