Bucky didn't need a warning. He knew how to follow. The moment she moved, he was hot on her heels. Trying to outrun the raptors proved to be an interesting experiment. It wasn't one he wanted to repeat. Those claws and teeth looked real nice and sharp up close. And it wasn't just one they were trying to get past. It was a pack of them and if Bucky knew one thing for sure about a pack, it was that the prey rarely survived.
He expected Pepper to go through the portal first and watch her back just in case one of those rows of teeth tried to go for her while her back was turned. That 'little' weapon of her's was a handy one though and was able to keep the raptors at bay just long enough for him to try and get to the portal. At the last second, she grabbed him by the wrist as she took another blast and tossed his ass through the portal like he was nothing.
On the other side, he only took that breath of relief when he heard her land next to him. He had landed on his back and he let out a little noise of happiness. "Let's not do that again, okay?"