If the other-dimensional Tony was suggesting what she thought he was, then Wanda would have gladly crossed the line into that weird territory. After all, she was unattached, bored, and how often did the opportunity come along for a menage a trois with two Tony Starks? Oh, well, just one Tony Stark, apparently. The prospect of only this singular stranger Tony was somewhat less exciting, particularly when the Tony she knew and was rather fond of was now very likely in mortal danger. Apparent charms of the new Tony aside, Wanda suspected that the portal would never lead to anywhere good. That Tony could handle himself she had no doubt, but she was a lot less certain that he could easily find what he was looking for and get back on his own soon.
The intruder and his unspoken indecent proposal fell to the wayside as the machine powered down and she went cautiously to examine it. The noise and the ache in her head was gone, which wasn't actually a comfort given the situation. If this portal worked the same as it had before then it might not turn on again until Tony found the gem on the other side, and that could be awhile without her connection to the thing to speed up the search. In the meantime, a lot of people were going to notice if Tony were missing. Wanda was already starting to form a plan, a completely crazy and foolish one, but that was usually how she operated. Before she could put that plan into action, though, she needed to find out where exactly Tony had gone.
First things first- "What's it like on the other side of the portal?" she demanded of the other Tony, brusque now without any hint that smile she'd conjured up for him before. Flirt all he wanted, he was still a stranger, a vital source of information, and- with any feelings of ease disappeared along with the real Tony- a potential threat. If he was the last, then she'd do her best to stall him here until the portal opened again and, if he wasn't, then there was a way in which he could help keep the secret.