He had no idea what kind of effect this would have on either of them, it could turn out very badly. Maybe one or both of them would become ill. But what was life without a little experimentation? Trying new things?
Look at what it had gotten him with Baba.
"I will allow you to take mine first." The unsaid threat was there, that if Lestat bolted after without the trade, there would be problems. They each had their own advantages over the other, but Eric was very certain his speed and strength outmatched his companion's.
He rolled up the sleeve of his shirt and held his wrist out.