I'm kinda confused, is Teresa actually a guy? And the Franco de Frank is actually a woman?
I mean, going by the character designs, they sure are. Franco certainly is not a feminine or androgynous man, but rather a every so slightly masculine woman.
And Teresa might just be a trap. I did read that chapter but I'm still not sure because;
That otaku guy thinks Teresa is a reverse trap, that usually a female pretending to be a guy. But I have my doubts about it because "that's a story for later" Arc called them a "reverse couple" that still implies that Franco is a guy but acts a a bride but I'm still no convinced.
TL;DR Teresa is a serial sexual offender if he's a guy.