Yeah, the situation is unfortunately difficult. A friend of mine actually flat out told me the other day to get a dog cause a tank of fish or a snake will never "love" me. Which, I my opinions on whether reptiles and fish are more capable emotionally than people think, but that is for another time. I'm finding reptile/fish people are of a "special breed" which "normal" people will not understand.
Anyway aside from moving in with the parents what other options could you pursue?
Possibilities:
-Get another less expensive apartment with the BF?
-Get another less expensive apartment with the BF and possibly other roommates?
-Get another less expensive apartment with other roommates?
-Rent a house
-Move in with another family member? aunt, uncle, cousin?
I know the goal is to save money but it sounds like your parents value their ignorance over their daughter.
Other alternatives:
-Force them out of their own home using the mafia or some awesome scheme involving cockroaches and sporks
-Force them out by having half of the people on this website to move into your parents' neighborhood and forcing reptile house warming parties for 6 months straight at their house
-Hit the lottery and not share it with them while you live in a mansion once owned by Ray Lewis or Cal Ripken Jr. and turn the basement is a reptile palace
-Buy a boat, live on the ocean
-Raid their house like a buccaneer would raid a port, take them hostage and make them walk the plank.