Bruce was highly unnerved by this, as he had never met Stark before and he shouldn't be aware of the Hulk. How had he got this knowledge? It had been kept very under wraps within HYDRA, as they were embarrassed at not being able to contain or control the beast they had accidentally helped create, and the underground resistance was silent about pretty much everything as a necessity for survival.

As a consequence he didn't take that hand, he merely blinked furiously for a second or two and then swallowed hard.

"Some things are best kept quiet, Mr. Stark."