It was a little disturbing to witness just how Cassie prioritized this costumed crime fighting thing, even for a career Avenger. Maybe because Tony was still lagging on accepting the fact that she had been alive for eighteen whole years and not a meager and delicate twelve, and, for Tony, that kind of eagerness had some wildly negative connotations. Cassie changed faster than Ms. Marvel and her magical girl sequence, not giving Tony much chance to lure her out of it with promises of dirtbikes, which he was pretty sure would work on Cassie, or ponies, which was a classic and had to be rooted in some little girl mytho-reality.
Pointedly not meeting Steve's eye because whatever non-verbal connection he expected them to maintain any more for the rest of eternity wouldn't even cut it until there was grovelling involved, Tony suggested, "Pump the breaks," with his hands up to slow Cassie down. "Don't you want to try it out a bit? I thought we could head out to the campus and you could get some practical testing ground experience in..." Steve could have, at the very least, not offered to put off his own gift. It would probably capture Cassie's imagination for ten minutes longer than the three seconds she spent being fascinated by a car. Steve was good at that kind of thing. Whatever he was doing, Tony was sure now that it was full-knowledge sabotage.