So I just thought of the weirdest Iida head cannon...
You and Iida are dating and yes you have done the nasty and sometimes when you’re changing the other girls/ boys will notice these weird red marks on your body. Some on your chest, back, stomach, and even your inner thighs. The red marks are very thin rectangles normally only lasting a day and a half.
When you finally notice the marks yourself you realize that while girls or bottoms in general have a habit of scratching, your boyfriend will do his adorable hand motions when he is about to cum, leaving those marks.
‘I guess he doesn’t realize how hard he can hit’ you think while looking at your back with about 6 marks.