Deal Breaker

In “The Big Bang Theory” episode, “The Codpiece Topology” Leonard is dating fellow-scientist Leslie.  At one point, Sheldon, Leonard, and Leslie have the conversation below:

Sheldon: I will graciously overlook the fact that she is an arrogant sub-par
scientist, who actually believes loop quantum gravity better unites quantum
mechanics with general relativity than does string theory. You kids have fun.

Leslie: Hang on a second. Loop quantum gravity clearly offers more testable
predictions than string theory.

Sheldon: I’m listening, amuse me.

Leslie: Okay, well, for one thing we expect quantii space-time to manifest
itself as minute differences in the speed of light for different colours.

Sheldon: Balderdash. Matter clearly consists of tiny strings.

Leslie: Are you going to let him talk to me like that?

Leonard: Okay, well, there is a lot of merit to both theories.

Leslie: No there isn’t, only loop quantum gravity calculates the entropy of
black holes. You agree with me, right, loop quantum gravity is the future of physics.

Leonard: Sorry Leslie, I guess I prefer my space stringy not loopy.

Leslie: Well, I’m glad I found out the truth about you before this went any
further.

Leonard: Truth, what truth? We’re talking about untested hypotheses, uh, it’s no
big deal.

Leslie: Oh, it isn’t, really? Tell me Leonard, how would we raise the children?

Leonard: I guess we let them wait until they’re old enough and let them choose
their own theory.

Leslie: We can’t let them choose, Leonard, they’re children. (Storms off.)

Leonard: Wait, where are you going?

Leslie: I’m sorry, I could have accepted our kids being genetically unable to
eat ice-cream or ever get a good view of a parade, but this? This is a deal
breaker. (Leaves.)

I hope the question below elicit some fascinating replies:

For You/you, what is a deal breaker in:

A HypnoDomme-hypnosub relationship?