(Y/N pov)

I was in the lab while Tony was out on another mission. I was just working on some little things for myself like I always do when Tony's out on a mission. I had me earphones in so I didn't hear Tony come home. He came up behind me and kissed my neck and scared me. Obviously I didn't know it was him so I turned around and tackled him to the ground. "Shit, Tony. I didn't know it was you sorry" I said getting up and putting my hand out for him to take. "It's fine. At least. I know you can handle yourself when I'm not here. But sorry it was partly my fault I did scare you." He said giving me a hug. I hugged him back. "Get dressed we going to a party tonight, with the other to celebrate another successful mission." He said so I went and took a shower and got dressed.

——— At the party———

(Tonys pov)

I was with Thor talking. I was scanning the room for Y/N. I eventually found her talking with Steve. He started to hit on her, he knows that she's mine. He was moving his hand up her leg and I was getting a little mad. I walked over to them and grabbed her hand and took her back to our room. As soon as the door shut I pinned her to the wall. "Tony what's wro..." I cut her off by smashing my lips on hers. "You have been a bad girl" I said as I broke the kiss, she looked at me confused. "What did I do Tony" she knew exactly what she did but she was going to play. "First of all you were letting Steve hit on you and you are mine. Second of all what's my name?" She bit her lip and looked into my eyes. "I'm sorry for doing that but I knew it would get you like this, and that's exactly how I wanted you. Daddy" she said with a massive smirk on her face. "Like I said you've been a bad girl" I said kissing her and then making my way down her neck. We took each other's clothes off of each other until we were both fully naked, I picked her up and she wrapped her legs around me.

I moved us to the bed. I moved a hand down to her clit and started to tease her knowing it will drive her crazy. "Please daddy" she pleaded "Please what baby girl" I said wanting her to beg. "Please fuck me daddy" I did as she asked. I lined myself up and pushed in her not giving her time to adjust. I was going at a normal pace until "Fuck daddy faster" I went as fast as I can. I kissed her neck leaving a very noticeable hickey on her so everyone knew that she was mine. "Oh god daddy I'm gonna cum" she said "I am too. Cum for me baby girl" With that she came and so did I. I fell next to her panting. "You are mine don't ever let someone touch you again. Okay?" I said, she didn't say anything she just straddle me and kissed me. "Round two?" She said with that look in her eye knowing I can't resist her.