Even so, keep looking into the other person's eyes if you can. This could take you beyond the sense of vulnerability into a bigger space. Try to stay with it if you can. If you must look away, notice what came up that caused you to break contact. Making eye contact takes us beyond the boundaries of ourselves, beyond the boundaries of the other, into the boundlessness of space.
Space can be very threatening.
Making eye contact with your partner by agreement is a way to experience the space and rest there. You've agreed to try this experiment, and you've agreed to fully encounter whatever you encounter. When you make eye contact for long enough, you pass beyond all the defenses into an open space. Rejoice in sharing this space, and claim it as your own. Continue the practice of making eye contact with your partner.