They needed to work through this and that's what Steve reminded himself when the temptation to just retreat all got too much. Tony's anxiety was mirrored in Steve as well, because the fact that this could damage them beyond repair was real. He took it slow, making sure he said what he meant, because putting his foot in his mouth was something that happened.
"I didn't plan ahead to sleep with you," Steve said with raised eyebrows. "I wasn't sure it would lead to that, I wasn't even sure you'd want what I wanted. Want."
Steve didn't know the first thing about love or being in it, with a tragic history that was best not thought about. He stood up because the anxious energy was all just too much and he couldn't just sit there anymore. "Would I be with him now if there wasn't someone else?" Steve asked as he crossed the porch. He couldn't fault Tony for wanting reassurance and Steve wanted to give it to him as much as he could, to put this behind them. "No." He reached out to take Tony's hand, holding his fingers gentle in his own but giving him the space to pull away. "And even if you'd said no, that you didn't want this? It still wouldn't be different because you have me, regardless of if you want me or not."